Developers are aware and have been trying to solve this for awhile now, but with no luck.
In reference to the GitHub issue you opened, I don’t think it has anything to do with OH 3.4. I’m still on OH 3.3 and have also noticed an increase in disconnects recently. Anecdotally, it seems that some users have experienced it more than others (well before 3.4 was released), while others may not be experiencing it at all. In my case, the disconnects stopped happening for awhile, and then started up again more frequently.