real-time video encoding is VERY computationally demanding.
And you have a lower-end 4 generation old CPU, so be realistic in expectations. Your scene setup shows some sophistication, and at one point, shows the beginning (0.1%) of rendering and encoding lag, so I'm guessing your setup is right on the limit. And dynamic bitrate shows some drops... but whether that is a LAN issue (something else consuming, or decreased upload bandwidth availability) or your PC being so busy that your PC's can't process enough network traffic to keep up ... no way to tell from an OBS log which that might be
I recommend monitoring hardware resource (CPU, GPU, RAM, etc) utilization to see if your system is being maxed out with your settings [Task manager’s Performance tab and/or Resource Monitor]
- it could be as simple as an unexpected background process driving your PC over a stable threshold.. or not
Do you have others on your LAN? are you doing any Internet bandwidth real-time utilization monitoring?