vsr 10 bolt keep locking back

hello first time posting on this site. I bought a tm vsr 10 about a year ago and i have upgraded most of the gun. Lately i have added an AA 90 degree trigger because i had a problem with the old 45 degree trigger i was using where the bolt would lock back every now and then and i would have to disassemble the gun to release it. It got to the point where i couldnt use my gun for months until i could afford to buy the 90 degree trigger. Anyways i fitted the new trigger on to the gun fine and it worked quite well for the first few shots. Eventually i noticed that the boltpull was very grindey and had a horrible scratching sound when i pulled it back and it got so bad that i couldnt pull the bolt back all the way however this only happend every now and then but soon i got the same problem i had with my old trigger where the bolt would lock back and the only way to release it was to disassemble it or push it really hard until it snaps forward. i thought it was my spring guide but i got a new one and the problem still seems to persist. I took the gun apart over and over again cleaning it and applying grease in the correct places. I checked if the return springs have snapped but nope, and most of my parts are brand new pretty much. I wanted to post this because i havent seen the issue anywhere else and i havent been able to use my gun for months even after investing alot of money to fix it.Thank you for taking the time to read this long post.



gun:tokyo marui vsr 10
parts:
action army reciever

action army m150 spring
action army teflon coated cylinder
action army piston,spring and spring guide
action army 90 degree trigger
malple leaf 50 degree hop up bucking
action army tight bore inner barrel

(a few teflon tape mods for air seal and custom barrel spacers)