I have tried playing with your mememe one too to make it longer by looping more than it does, and I have got the same result as with watchdogs, I think there might be a file size limit or a frame limit or something with these bootanimations for magisk or op7pro
If you're going to directly push to your system, make sure to debloat some system apps. With the latest update, OP has filled it up to the max so you can't push any "big" bootanimation files. However, with magisk, there shouldn't be any issues.
I'll probably add a tutorial or something in the following days.