diff --git a/Jellyfin.Api/Controllers/TvShowsController.cs b/Jellyfin.Api/Controllers/TvShowsController.cs
index e45a100b77..0d477ef95b 100644
--- a/Jellyfin.Api/Controllers/TvShowsController.cs
+++ b/Jellyfin.Api/Controllers/TvShowsController.cs
@@ -277,8 +277,15 @@ public class TvShowsController : BaseJellyfinApiController
 
         if (startItemId.HasValue)
         {
+            // The start item may be an alternate version, which is not part of the episode listing; start from its primary episode instead.
+            var startId = startItemId.Value;
+            if (_libraryManager.GetItemById<Video>(startId)?.PrimaryVersionId is { } primaryVersionId)
+            {
+                startId = primaryVersionId;
+            }
+
             episodes = episodes
-                .SkipWhile(i => !startItemId.Value.Equals(i.Id))
+                .SkipWhile(i => !startId.Equals(i.Id))
                 .ToList();
         }
 
diff --git a/Jellyfin.Server.Implementations/Item/BaseItemRepository.TranslateQuery.cs b/Jellyfin.Server.Implementations/Item/BaseItemRepository.TranslateQuery.cs
index f33a65a703..bb5db79677 100644
--- a/Jellyfin.Server.Implementations/Item/BaseItemRepository.TranslateQuery.cs
+++ b/Jellyfin.Server.Implementations/Item/BaseItemRepository.TranslateQuery.cs
@@ -513,12 +513,17 @@ public sealed partial class BaseItemRepository
         if (filter.IsResumable.HasValue)
         {
             var hasSeries = filter.IncludeItemTypes.Contains(BaseItemKind.Series);
+            var userId = filter.User!.Id;
+            var isResumable = filter.IsResumable.Value;
+
+            // In-progress user data rows; alternate versions track their own progress.
+            var inProgress = context.UserData
+                .Where(ud => ud.UserId == userId && ud.PlaybackPositionTicks > 0);
+            var resumableItemIds = inProgress.Select(ud => ud.ItemId);
 
             if (hasSeries)
             {
-                var userId = filter.User!.Id;
                 var seriesTypeName = _itemTypeLookup.BaseItemKindNames[BaseItemKind.Series];
-                var isResumable = filter.IsResumable.Value;
 
                 // Aggregate per series in a single GROUP BY pass, instead of three full scans.
                 var seriesEpisodeStats = context.BaseItems
@@ -539,23 +544,24 @@ public sealed partial class BaseItemRepository
                     .Where(s => s.HasInProgress || (s.HasPlayed && s.HasUnplayed))
                     .Select(s => s.SeriesId);
 
-                // Non-series items: resumable if PlaybackPositionTicks > 0
-                var resumableItemIds = context.UserData
-                    .Where(ud => ud.UserId == userId && ud.PlaybackPositionTicks > 0)
-                    .Select(ud => ud.ItemId);
-
                 baseQuery = baseQuery.Where(e =>
                     (e.Type == seriesTypeName && resumableSeriesIds.Contains(e.Id) == isResumable)
                     || (e.Type != seriesTypeName && resumableItemIds.Contains(e.Id) == isResumable));
             }
             else
             {
-                var resumableItemIds = context.UserData
-                    .Where(ud => ud.UserId == filter.User!.Id && ud.PlaybackPositionTicks > 0)
-                    .Select(ud => ud.ItemId);
-                var isResumable = filter.IsResumable.Value;
                 baseQuery = baseQuery.Where(e => resumableItemIds.Contains(e.Id) == isResumable);
             }
+
+            if (isResumable)
+            {
+                // Multi-version items surface as the version that was actually played.
+                // When several versions of the same item are in progress, keep only the most recently played one.
+                baseQuery = baseQuery.Where(e => !context.BaseItems
+                    .Where(s => s.Id != e.Id && (s.PrimaryVersionId ?? s.Id) == (e.PrimaryVersionId ?? e.Id))
+                    .Any(s => inProgress.Where(su => su.ItemId == s.Id).Max(su => su.LastPlayedDate)
+                        > inProgress.Where(eu => eu.ItemId == e.Id).Max(eu => eu.LastPlayedDate)));
+            }
         }
 
         if (filter.ArtistIds.Length > 0)
diff --git a/Jellyfin.Server.Implementations/Item/OrderMapper.cs b/Jellyfin.Server.Implementations/Item/OrderMapper.cs
index d327b218a9..eeeeda8193 100644
--- a/Jellyfin.Server.Implementations/Item/OrderMapper.cs
+++ b/Jellyfin.Server.Implementations/Item/OrderMapper.cs
@@ -34,7 +34,10 @@ public static class OrderMapper
             (ItemSortBy.AirTime, _) => e => e.SortName,
             (ItemSortBy.Runtime, _) => e => e.RunTimeTicks,
             (ItemSortBy.Random, _) => e => EF.Functions.Random(),
-            (ItemSortBy.DatePlayed, _) => e => e.UserData!.Where(f => f.UserId.Equals(query.User!.Id)).OrderBy(f => f.CustomDataKey).FirstOrDefault()!.LastPlayedDate,
+            (ItemSortBy.DatePlayed, not null) => e =>
+                jellyfinDbContext.UserData
+                    .Where(w => w.UserId == query.User.Id && (w.ItemId == e.Id || w.Item!.PrimaryVersionId == e.Id))
+                    .Max(f => f.LastPlayedDate),
             (ItemSortBy.PlayCount, _) => e => e.UserData!.Where(f => f.UserId.Equals(query.User!.Id)).OrderBy(f => f.CustomDataKey).FirstOrDefault()!.PlayCount,
             (ItemSortBy.IsFavoriteOrLiked, _) => e => e.UserData!.Where(f => f.UserId.Equals(query.User!.Id)).OrderBy(f => f.CustomDataKey).Select(f => (bool?)f.IsFavorite).FirstOrDefault() ?? false,
             (ItemSortBy.IsFolder, _) => e => e.IsFolder,
diff --git a/tests/Jellyfin.Controller.Tests/Entities/BaseItemTests.cs b/tests/Jellyfin.Controller.Tests/Entities/BaseItemTests.cs
index 664821815b..c0a2b0ecca 100644
--- a/tests/Jellyfin.Controller.Tests/Entities/BaseItemTests.cs
+++ b/tests/Jellyfin.Controller.Tests/Entities/BaseItemTests.cs
@@ -136,6 +136,22 @@ public class BaseItemTests
         Assert.Null(primary.GetAlternateVersion(Guid.NewGuid()));
     }
 
+    [Fact]
+    public void GetAllVersions_FromAnyVersion_ReturnsEveryVersionOnce()
+    {
+        var (primary, alt1, alt2) = SetupVersionGroup();
+
+        foreach (var source in new[] { primary, alt1, alt2 })
+        {
+            var versions = source.GetAllVersions();
+
+            Assert.Equal(3, versions.Count);
+            Assert.Contains(versions, v => v.Id.Equals(primary.Id));
+            Assert.Contains(versions, v => v.Id.Equals(alt1.Id));
+            Assert.Contains(versions, v => v.Id.Equals(alt2.Id));
+        }
+    }
+
     [Fact]
     public void PropagatePlayedState_MarksAlternateVersions_AndResetsPositionByDefault()
     {