(Dis)connect from/to VPN causes high %CPU on Win10

Using Windscribe VPN v1.81b83 and Cryptomator v1.3.4 on Windows 10.

When I boot Windows, both Windscribe and Cryptomator come up fine at startup with no obvious performance issues.However, if I disconnect from the VPN or later reconnect, Cryptomator starts using 50+% of CPU on an Intel i7 970 (12 vCores).

Here I’ve included procexp stacks from two high-cpu Cryptomator threads when this happens. I have a strong suspicion that this has something to do with the vault being mounted as a network share. The VPN is configured to allow LAN traffic when its firewall is enabled. I am happy to do further debugging when this happens. Please advise, thanks.

ntoskrnl.exe!KeSynchronizeExecution+0x60a6
ntoskrnl.exe!KeWaitForMutexObject+0x1070
ntoskrnl.exe!KeWaitForMutexObject+0x9ee
ntoskrnl.exe!KeWaitForMutexObject+0x1c9
ntoskrnl.exe!KeTestAlertThread+0x3f3
ntoskrnl.exe!KeWaitForMutexObject+0x2c10
ntoskrnl.exe!KiCheckForKernelApcDelivery+0x25
ntoskrnl.exe!ObReferenceObjectSafeWithTag+0x7e
ntoskrnl.exe!ObReferenceObjectByHandle+0x2b0
ntoskrnl.exe!ObReferenceObjectByHandle+0x2e
afd.sys+0x56f29
afd.sys+0x56d55
afd.sys+0x4d307
ntoskrnl.exe!IofCallDriver+0x59
ntoskrnl.exe!NtDeviceIoControlFile+0xe9e
ntoskrnl.exe!NtDeviceIoControlFile+0x6dc
ntoskrnl.exe!NtDeviceIoControlFile+0x56
ntoskrnl.exe!setjmpex+0x7e03
ntdll.dll!ZwDeviceIoControlFile+0x14
mswsock.dll!Tcpip6_WSHGetSockaddrType+0x637
WS2_32.dll!select+0x1d0
nio.dll!Java_sun_nio_ch_WindowsSelectorImpl_00024SubSelector_poll0+0x168
jvm.dll!JVM_GetManagementExt+0xe9cec

ntoskrnl.exe!KeSynchronizeExecution+0x60a6
ntoskrnl.exe!KeWaitForMutexObject+0x1070
ntoskrnl.exe!KeWaitForMutexObject+0x9ee
ntoskrnl.exe!KeWaitForMutexObject+0x1c9
ntoskrnl.exe!KeTestAlertThread+0x3f3
ntoskrnl.exe!KeWaitForMutexObject+0x2c10
ntoskrnl.exe!KeSetEvent+0x69e
ntoskrnl.exe!KeSetEvent+0x96
ntoskrnl.exe!NtDeviceIoControlFile+0xb4d
ntoskrnl.exe!NtDeviceIoControlFile+0x56
ntoskrnl.exe!setjmpex+0x7e03
ntdll.dll!ZwDeviceIoControlFile+0x14
mswsock.dll+0x1352
mswsock.dll!Tcpip6_WSHGetWildcardSockaddr+0x2809
WS2_32.dll!ioctlsocket+0xe8
nio.dll!Java_sun_nio_ch_WindowsSelectorImpl_resetWakeupSocket0+0x2f
jvm.dll!JVM_GetManagementExt+0xe9cec

Apologies, but it’s been two weeks and nobody has any idea about this? The Windscribe folks couldn’t come up with anything either. Anyone?

I’ve now confirmed via the link below that Windscribe VPN does forcible disconnection of TCP sockets. I think this is likely to be causing the high CPU that I see from Cryptomator. Can the developers please check this and see if this can be patched somehow?

Bump…anyone interested in venturing a guess even?