Transmission jerking, bogging strong vibrations no codes

Hi! This is my first post here, and I would like some advice on what to do about my situation.
I recently rebuilt my 2011 ford fiesta transmission with everything new, clutch assembly, forks, TCM, and updated seals and I've been having this issue where the car ***** erratically, jerks going uphill, and sometimes on plain (like if the transmission were struggling trying to shift) most noticeable on 1st to 2nd shifts and rarely when the car is going fast over 3rd gear, more noticeable uphill as I said previously, I have no transmission faults or codes, neither engine codes, but this issue is driving me crazy, I bought a new TCM believing that the one I bought was faulty but the problem persists, sometimes when I disconnect the battery for a long period the issue almost goes away and the shifts are nearly perfect, but after some time it starts behaving the same way.

I scrapped all the paint under the grounds (covering the ones behind the battery box) but had no luck solving my issue, doing the TCM relearn using forscan and had no issues too, TCM is programmed with forscan too but still the same thing over and over.

Does someone have any advice on this? Thanks so much for any information you can provide.