So these are the ones that caught my eye:
goroutine 58705 [select, 37 minutes]:
github.com/thejerf/suture.(*Supervisor).RemoveAndWait(0xc0001a8f00, 0x200000033, 0x0, 0x0, 0x0)
C:/go/pkg/mod/github.com/thejerf/suture@v3.0.2+incompatible/supervisor.go:739 +0x1d9
github.com/syncthing/syncthing/lib/model.(*model).stopFolder(0xc000182780, 0xc01be169c0, 0xb, 0xc0115264c0, 0x14, 0x0, 0xc0115264e0, 0x1d, 0x2, 0xc00eb07b00, ...)
C:/Syncthing/lib/model/model.go:469 +0xde
github.com/syncthing/syncthing/lib/model.(*model).restartFolder(0xc000182780, 0xc01be169c0, 0xb, 0xc0115264c0, 0x14, 0x0, 0xc0115264e0, 0x1d, 0x2, 0xc00eb07b00, ...)
C:/Syncthing/lib/model/model.go:528 +0x2fa
github.com/syncthing/syncthing/lib/model.(*model).CommitConfiguration(0xc000182780, 0x1e, 0xc009a08a00, 0xf, 0xf, 0xc0099b3800, 0x7, 0x7, 0x1, 0xc01be16d20, ...)
C:/Syncthing/lib/model/model.go:2477 +0xaf8
github.com/syncthing/syncthing/lib/config.(*wrapper).notifyListener(0xc000416000, 0x10f5860, 0xc000182780, 0x1e, 0xc009a08a00, 0xf, 0xf, 0xc0099b3800, 0x7, 0x7, ...)
C:/Syncthing/lib/config/wrapper.go:220 +0x131
github.com/syncthing/syncthing/lib/config.(*wrapper).notifyListeners.func1(0xc000416000, 0xc0097e2c00, 0xc0097e3000, 0x10f66a0, 0xc012231a60, 0x10f5860, 0xc000182780)
C:/Syncthing/lib/config/wrapper.go:211 +0xed
created by github.com/syncthing/syncthing/lib/config.(*wrapper).notifyListeners
C:/Syncthing/lib/config/wrapper.go:210 +0x1a7
goroutine 42677 [chan send, 39 minutes]:
github.com/syncthing/syncthing/lib/model.(*sendReceiveFolder).copierRoutine(0xc000028f00, 0xc00bd8dbc0, 0xc00bd8db60, 0xc00bd8dc80)
C:/Syncthing/lib/model/folder_sendrecv.go:1343 +0xc10
github.com/syncthing/syncthing/lib/model.(*sendReceiveFolder).pullerIteration.func2(0xc000028f00, 0xc00bd8dbc0, 0xc00bd8db60, 0xc00bd8dc80, 0x10f66a0, 0xc01b504f20)
C:/Syncthing/lib/model/folder_sendrecv.go:246 +0x50
created by github.com/syncthing/syncthing/lib/model.(*sendReceiveFolder).pullerIteration
C:/Syncthing/lib/model/folder_sendrecv.go:244 +0x4bc
goroutine 57546 [select, 44 minutes]:
github.com/syncthing/syncthing/lib/protocol.(*rawConnection).Request(0xc003f860d0, 0x10f8a20, 0xc0010368c0, 0xc0003d1f80, 0xb, 0xc0132c5f80, 0x66, 0x3c0000, 0x20000, 0xc01472eae0, ...)
C:/Syncthing/lib/protocol/protocol.go:312 +0x31e
github.com/syncthing/syncthing/lib/protocol.wireFormatConnection.Request(0x11046a0, 0xc003f860d0, 0x10f8a20, 0xc0010368c0, 0xc0003d1f80, 0xb, 0xc00a281ce0, 0x66, 0x3c0000, 0x20000, ...)
C:/Syncthing/lib/protocol/wireformat.go:40 +0x163
github.com/syncthing/syncthing/lib/model.(*model).requestGlobal(0xc000182780, 0x10f8a20, 0xc0010368c0, 0x35479b5ca86aca9a, 0x4fcb3ab03b6fdd2, 0xfb26b2562e7b33b3, 0xe5860f47d562056b, 0xc0003d1f80, 0xb, 0xc00a281ce0, ...)
C:/Syncthing/lib/model/model.go:2054 +0x499
github.com/syncthing/syncthing/lib/model.(*sendReceiveFolder).pullBlock(0xc000bdec00, 0xc013527400, 0xc01472eae0, 0x20, 0x20, 0x3c0000, 0x5036989b00020000, 0xc00aa22900)
C:/Syncthing/lib/model/folder_sendrecv.go:1458 +0x3af
github.com/syncthing/syncthing/lib/model.(*sendReceiveFolder).pullerRoutine.func1(0x10f66a0, 0xc016708520, 0xc00345d880, 0x20000, 0xc000bdec00, 0xc013527400, 0xc01472eae0, 0x20, 0x20, 0x3c0000, ...)
C:/Syncthing/lib/model/folder_sendrecv.go:1405 +0x102
created by github.com/syncthing/syncthing/lib/model.(*sendReceiveFolder).pullerRoutine
C:/Syncthing/lib/model/folder_sendrecv.go:1401 +0x334
goroutine 32332 [select]:
github.com/syncthing/syncthing/lib/protocol.(*rawConnection).writerLoop(0xc003f860d0)
C:/Syncthing/lib/protocol/protocol.go:685 +0x2cb
created by github.com/syncthing/syncthing/lib/protocol.(*rawConnection).Start
C:/Syncthing/lib/protocol/protocol.go:238 +0x8e
goroutine 32282 [semacquire, 37 minutes]:
sync.runtime_Semacquire(0xc012231a68)
c:/go/src/runtime/sema.go:56 +0x49
sync.(*WaitGroup).Wait(0xc012231a60)
c:/go/src/sync/waitgroup.go:130 +0x6b
github.com/syncthing/syncthing/lib/config.(*wrapper).Unsubscribe(0xc000416000, 0x10f5f20, 0xc0014c2380)
C:/Syncthing/lib/config/wrapper.go:165 +0x229
github.com/syncthing/syncthing/lib/watchaggregator.(*aggregator).mainLoop(0xc0014c2380, 0xc00b466c60, 0xc01503c9c0, 0x1109360, 0xc000416000, 0x10f8ea0, 0xc000198e70)
C:/Syncthing/lib/watchaggregator/aggregator.go:161 +0x7b5
created by github.com/syncthing/syncthing/lib/watchaggregator.Aggregate
C:/Syncthing/lib/watchaggregator/aggregator.go:132 +0xf7
I am not sure why unsubscribe even waits for a waiter?
Also, seems the writer loop for that connection is going yet there is a number of requests hanging.