I've started to have this problem 2 months ago where I wouldn't be able to do anything with my (R2) . At first, I thought there was something wrong with my (R2) or the sensitivity I had to press down on it, but when I went to test it out in other games it was completely fine. The same day, I went into training so I could figure out how to get it to work and then... It worked! After repeatedly pressing (R2) , but I was only able to shoot once after that, but when I died , I was able to shoot throughout the whole training mission with no problems.
Next, I started a regular mission, came across the same problem, except the (R2) trigger functioned "sometimes" which lasted the whole match and throughout parts of the day. 1-3 days later , I was able to use my (R2) without any difficulties until 5/21/19 and 5/22/19.
I not entirely sure what causes this but I know for certain that it doesn't involve latency nor my physical controller.
----------------------UPDATE-------------------------------------------
Turns out the problem was with my (R2) trigger where I had to press down harder than usual to get it to function in most games I play, but when it came to Spacelords, it was extremely difficult to get it to work until I figured out to press down on top of the (R2) trigger instead of directly on it (if that makes sense). I'm hoping there would be a option to adjust the sensitivity of (L2 & R2) triggers to potentially fix this inconvenience in future updates