Splotchy paint sheen
Just completed painting a 2nd coat of water-base semi-gloss on a wall that has been painted several times before. A few dings were patched with joint compound and covered with Bullseye 1-2-3 waterbase primer. Entire wall was very lightly sanded. Results: very uneven sheen in parts especially near the bottom of the wall. Doesn't seem to be a correlation between the low-sheen spots and the repaired ding areas. However, one of the low-sheen areas is where a previously painted section ended and a follow-up section meet.
Paint is mid-range quality, brush is near Purdy quality -- brushed because the whole area being painted is small, approx. 55 SF. The paint dried really quickly -- Honolulu, 80-85 degrees; had to paint rather quickly to keep up with the paint drying. (I do have a tendency toward perfectionism, and will often go back to smooth out the meeting of a prior painted section when applying more paint below it to make sure I am getting an even coat.)
Before I try merely painting over the area again, any ideas what is happening? Maybe I just didn't get the paint on evenly? Maybe I am going over the previously painted sections too much? Would a roller make a difference? Advice?