For some reason i cant reach the send button, its under the keyboard and pressing the back button (to close the keyboard) disregards all changes and closes the DM screen. I think this might be fixable in a “easy” way where if the keyboard is open, the back button only closes the keyboard (and maybe do the save draft thing for DMs as well if possible)
My back button always closes the keyboard before performing an action on the screen, is this maybe a setting on your phone that could be changed as my keyboard acts as you suggested within PMs. One tap on back closes the keyboard to reveal the send button, a second will back out of that screen.