I was torn between where to place this post... It's part feedback in explaining my experience, part request for advice, part information for others about a setup / mistake to avoid. The other thing to note is that I am not 100% sure on what is causing this....
So with the caveats out of the way... Over the last few months I have noticed that when transitioning to different modes using my Samsung Buttons, I end up in this cycle of switching from one Mode to another in rapid succession, seemingly requiring me to restart two of my HE hubs. Up until just recently (10-15 minutes ago) I thought this was due to multiple button presses being recorded for my button in the Kitchen, which I hope to have resolved earlier today after re-pairing the device.
After using another Samsung button, this time in my Study, to initiate a mode transition, I experienced the same mode flickering. I looked at the Events for the button device and did not see the multiple Events like I had seen for the button in the Kitchen, which I had resolved earlier today.
My next thing to investigate was the Hub Mesh Mode synchronisation. I found I had setup two hubs that referred to each other in order to sync their modes. Perhaps not the ideal setup, but I expect my rationale was that if, for any reason, I chose to change the mode on one of the hubs, I wanted the other to also reflect the change. Previously I have not experienced any issues initiating the mode change in the Modes page, accessed from Settings, only in the last 4-6 weeks, and only when initiating the mode change from, in this case, within an RM rule.
I have made the mode synchronisation now only in one direction, which is all I will likely need. Still interesting to understand / know why this may be the case, if only to warn people against this setup, if it is a known behavior.