Reproduction steps:
1. Open the attached project "ReproProj"
2. Open Build Profiles (File > Build Profiles)
3. Select Development Build
4. Click “Build And Run“
5. In Player, select “Load ProfilingScene“
6. Open Memory Profiler (Window > Analysis > Memory Profiler)
7. Click “Capture Snapshot“
8. In Player, select “Load MainScene“
9. Repeat steps from 5 to 7
10. In Memory Profiler, select “Compare Snapshots”
11. Select both snapshots
12. Click “All Of Memory“ tab
13. Observe the items and memory of "Managed > Managed Objects > System.WeakReference<UnityEngine.Events.UnityEventBase>"

Expected result: 1 item exists and Size Difference is 0
Actual result: Size Difference is about 62.8 KB and multiple items are present

Reproducible with: 6000.4.0b3, 6000.5.0a4
Could not test with: 6000.0.65f1, 6000.3.3f1 (Library\PackageCache\com.unity.scriptablebuildpipeline@ca3e2d96aa2f\Editor\Interfaces\IBuildCache.cs(19,46): error CS0234: The type or namespace name 'GUID' does not exist in the namespace 'UnityEngine')

Reproducible on:
Windows Standalone Player
Play Mode

Testing environment: Windows 10 Enterprise 21H2
Not reproducible on: No other environment tested