Built my trans it's been fine now it's lagging gears bad. For instance in first gear I have to baby it and let it off to get it to shift it's like that all the way thru but.... If standing on it it'll shift just fine. PCM issue?

Adjust bands

Did like 2weeks ago when I put my billet strut In it's done this before let it sit overnight and the next morning it worked fine

It really sounds like a band issue. I would try backing it off a 1/4 turn and see if that helps

Tight band will make your trans lag?

I think a loose band will actually cause your condition

I've seen the opposite to tight and it will hang in gear longer.