According to the OBS log, most of the threads you have running show ndi.plugins.ipcam.x64 in the thread's call stack. An example is below:
00000084922FCF18 00007FFDF8D8BE14 0000000000000002 0000019903EC0230 000001997EB3EC40 00007FFD00000000 ntdll.dll!0x7ffdf8d8be14
00000084922FCF20 00007FFDF5C380FC 0000000000000A9C 0000000000000103 0000019903E3CBE0 0000000000000A84 mswsock.dll!0x7ffdf5c380fc
00000084922FCFC0 00007FFDF5C4DE0B 0000000000000A84 00000199040B49B0 00007FFD7985EE98 00000084922FD124 mswsock.dll!0x7ffdf5c4de0b
00000084922FD0C0 00007FFDF7263E74 0000000000000002 0000000000000000 0000970F860120D4 002277BF00000000 ws2_32.dll!0x7ffdf7263e74
00000084922FD170 00007FFD796B6199 0000000000000010 0000971B2A6D5038 0000970F860120D4 0000000000000013 processing.ndi.plugins.ipcam.x64.dll!0x7ffd796b6199
00000084922FF6C0 00007FFD796B53A9 0000000000000000 0000019903EAA8B0 0000000000000000 0000000000000000 processing.ndi.plugins.ipcam.x64.dll!0x7ffd796b53a9
00000084922FF700 00007FFD7967AED9 0000019903FA9DD0 0000000000000000 0000000000000000 0000000000000000 processing.ndi.plugins.ipcam.x64.dll!0x7ffd7967aed9
00000084922FF730 00007FFD79710DC0 0000000000000000 0000000000000000 0000000000000000 0000000000000000 processing.ndi.plugins.ipcam.x64.dll!0x7ffd79710dc0
The calling stack of this thread shows OBS invokes the NDI plugin.dll. Then, the Microsoft mswsocket.dll (WinSock programming API) gets called towards the top. There are many threads doing this and the IP network camera plugin never closes down.
Your logs show you got a lot of camera plugins running. I see in one log with 16 camera plugin instances. Do you even have the proper networking bandwidth support to be stable to support all these cameras?
Lets assume you have a 100Mbps (not Gigabit 1000) local network infrastructure and that an IP camera setup to send MJPEG sends 24Mbps data over the local network. If you got multiple IP cameras as NDi sources (lets say 16, you are already overloading the network (16 x 24Mbps = 384Mbps > 100Mbps). Include also the traffic from your return stream from Twitch/YouTube and what you are sending up to the Twitch/YouTube ingest server and now you are overloading you local area network even more. So yes, if you got a lot of cameras all sending MJPEG data over your 100Mbps network, you have network bandwidht overload. Your networked applications will have instability. your network itself will have shitload of dropped packets.
This is just an example for you to ponder if you need to make networking infrastructure changes to Gigabit, change data format to H.264 rather than MJPEG, and/or reduce the number of IP cameras.
As mentioned earlier though, I would go update the HW Newtek driver and the OBS NDI Plugin. If all this doesnt work, to talk to NewTek.