Solved
Kepware is disconnecting from thingworx
For the random interval of time Kepware gets disconnected from thingworx (cloud server)
1. There was a similar problem before:
- "Connected with Kepware Server but things stay disconnected on Thingworx":
https://community.ptc.com/t5/ThingWorx-Developers/Connected-with-Kepware-Server-but-things-stay-disconnected-on/td-p/732577
https://community.ptc.com/t5/ThingWorx-Developers/Connected-with-Kepware-Server-but-things-stay-disconnected-on/td-p/747385 - "My industrial thing is disconnecting": https://community.ptc.com/t5/ThingWorx-Developers/my-industrial-thing-is-disconnecting/td-p/700601
2. Article - "WebSocket disconnect detection handling between ThingWorx Platform and KEPServerEX/ThingWorx Industrial Connectivity": https://www.ptc.com/en/support/article/CS309030