In my case the problem strikes under Android in DESKTOP versions of Facebook AND TWITTER sites (I didn't test FB and TW applications), no matter everything else (Android 6 or 9, Samsung or Gboard Google keyboards, with or sans predictive, etc); it does NOT happen in Android mobile versions of the sites, nor on any other sites than FB and TW, nor in Windows, etc.
Since it has existed and been reported for a couple years yet never been fixed, it appears the big ones (here Facebook, Twitter, Google) firmly want it to continue striking and to NOT get corrected. Probably part of their policy of forcing users into the intentionally debilitated so-called "mobile" versions of sites in order to reduce the user's powers, choices and general efficiency.
I would so much be in error on this... but little hope remains.
Versailles, Tue 10 Sep 2019 17:21:15 +0200