Reproduction steps:
1. Open the user's attached project
2. Open the Scene 'Scenes/MainMenu'
3. Enter Play mode
4. Click on 'Host (Server + Client)'
5. Press Esc to open the Inventory UI
6. Repeatedly click the left mouse button and Esc

Expected result: The editor crashes after some time
Actual result: The editor does not crash

Reproducible with: 2020.3.4f1, 2020.3.18f1, 2021.1.20f1
Not reproducible with: 2021.2.0a15, 2021.2.0b11, 2022.1.0a8
Couldn't test with: 2019.4.30f1, 2020.3.3f1, 2021.2.0a1, 2021.2.0a14 (Issues with downgrading/upgrading)

Note:
The crash happens with different stack traces, with most of them mentioning Playables in some way.

Stack traces:
#0 0x0000010ed26084 in PreOrderPlayableTraverser::Traverse(DirectorVisitorInfo&)
#1 0x0000010ed2b883 in PreOrderPlayableTraverser::RecursiveVisit(DirectorVisitorInfo&, Playable*, float, PlayState, float, float, double, int)
#2 0x0000010ed260b5 in PreOrderPlayableTraverser::Traverse(DirectorVisitorInfo&)
#3 0x0000010ed2b883 in PreOrderPlayableTraverser::RecursiveVisit(DirectorVisitorInfo&, Playable*, float, PlayState, float, float, double, int)
#4 0x0000010ed260b5 in PreOrderPlayableTraverser::Traverse(DirectorVisitorInfo&)

#0 0x00000106be2cab in Playable::Disconnect(Playable*, int)
#1 0x00000106c0386c in PlayableGraph::SchedulePlayableDestruction(HPlayable const&)
#2 0x00000106c043be in PlayableGraph::DestroyRecursive(Playable*)
#3 0x00000106c04393 in PlayableGraph::DestroyRecursive(Playable*)
#4 0x00000106c04393 in PlayableGraph::DestroyRecursive(Playable*)

#0 0x007fff2046492e in __pthread_kill
#1 0x007fff203e8406 in abort
#2 0x007fff202c8165 in has_default_zone0
#3 0x007fff202cb2aa in malloc_report
#4 0x0000010ddb0eca in MemoryManager::Deallocate(void*, char const*, int)

#0 0x00000161e737e9 in mono_object_get_class
#1 0x0000010ef7099e in scripting_object_get_class(ScriptingObjectPtr)
#2 0x0000010eecbb57 in Playable::CallOnGraphStart()
#3 0x0000010eecb71f in Playable::ProcessPlayState(DirectorVisitorInfo const&)
#4 0x0000010eecbde8 in Playable::PrepareFrameVisitor(DirectorVisitorInfo&)