Getting air in the lines somehow

I rebled them, held and the longer I held it would go down very slowly and then would need pumped up again like I never bled them. I ordered the drdiff MC and if that’s not it I’m gonna have to dig through it again
This. Right here, this is your clue.
The pedal is dropping. Thats a leak. Be it master cyl bypassing or a loose fitting or whatever.