Mansfield 160 w/New flush valve and gasket is still leaking

I have 3 mansfield 160 toilets; 2 of them were becoming hard to flush so I changed out the flush valves and then the gaskets but they are both still leaking and I can't figure out why. I took the parts off and compared them with the one mansfield toilet with the original parts to make sure they were correct and they are. I made sure the gasket was sitting where it is supposed to be and it appears to be correct. The only way I can get them to stop leaking is to push down on the flush valve with my had but it only stays that way for a few seconds and you can visibly see the flush valve pop back up. I'm not sure what to check next. I am having to shut the water off between each use. Any advise. The toilets are only 3 years old.

Just in case you want to follow my thread, I am having a similar problem, but with a different model. I did not consider this a dual post (just saying in case any moderators say anything).

https://terrylove.com/forums/showthread.php?t=32284

Dknight, how long ago did you change the gaskets? If it was just recently, I have found that the new gaskets may take a little bit of time to form a water tight seal. A few years back, I had a mansfield toilet very similar to the 160, and I had to flush it multiple times before it finally managed to create a tight seal.