Things happen between movies Adywan. Poe is right next to the girl who helped save his BB unit along with his new best pal Finn but he would wait until the ending of the next movie to say “oh, thanks by the way. Rey, right ?” Doesn’t make any sense. Not a huge continuity issue, but still it felt weird and forced at the end of TLJ.
In this specific case nothing could’ve happened between them between the movies. Maybe between scenes, but not necessarily. I see your point though.
Yeah, this is something the audience can assume happened off-camera. To me it just feels odd for two of our principal characters to introduce themselves to eachother for the first time after two full movies.