Hi all,
I have described similar WiFi disconnects before on these forums ... and I have found them on three different 2018 MBP 15s and now on a 2019 MBP 15. Same story on all of these machines, and the WiFi disconnects are not true disconnections as the WiFi hardware is still working, and for me at SNR=45dBm to 50dBm, i.e., at extremely strong signal-to-noise ratios. I find them on the 5GHz bands with no nearby routers on the same channel, I find them in the middle of the morning when no neighbors are up and on WiFi. In my hands these WiFi issues are relatively rare (a handful of times per day), they are random (occurring under all types of circumstances), and they are often intermittent (meaning that they often fix themselves after a minute or two), but I've also waited for over 15 hours without the WiFi issue fixing itself. On the other hand, these WiFi issues can always be fixed by simply stopping and restarting the WiFi service on the offending T2 MBP, no need to restart the router. While the T2 MBPs are experiencing WiFi problems, all of my other computers, including other non-T2 MBPs, an iMac, a Mac mini, a couple PCs running either Windows or Linux, and several Raspberry Pis, all maintain WiFi without problems while the T2 MBPs are suffering these WiFi troubles.
So, in my hands, the only common thread linking these WiFi troubles are the T2 MBPs, the T1 MBPs and older Apple computers do not experience these WiFi problems. I have also used Wireshark to capture the few packets that the T2 MBPs are sending/receiving even while they are suffering their WiFi disconnects. I have also seen pings go from 0% loss (i.e., WiFi working properly) to 99% loss (i.e., WiFi not working properly) but not 100% loss --- WiFi is still operative at some low level, in other words, but at a level so low that services often time-out before a connection is established.
These WiFi issues cause numerous other WiFi related problems, such as broken ssh pipes, broken rsync file transfers, failed Time Machine backups, failed Software Update updates, failed AirDrops midway through transfers, failed Safari loads, failed Mac App Store updates, disconnected VNC sessions, beach balling of Internet video playbacks, failed Mail sends, etc.
Solouki