There is an option "Automatic resize/recompress picture if needed" that you probably unchecked.
I see you could post pictures in the comments and that some pictures on https://www.imcdb.org/movie.php?id=318913 are waiting to be validated by an admin but I doubt they would be acceptable.
If things disappear, it is usually meaning that they were not acceptable.
From what other admins said, there were already things that were rejected for that one. So at some point you should stop trying...
Same for re-creating accounts each time: you were banned for bad behavior and useless contents.

I had general problems with this website. It doesn't let me upload pictures, I try to add pictures for the TMNT 2003 entry that I made and it doesn't let me. If anyone else encounters this problem, please write it in the comments.

P.S: also, if you want to add pictures to my TMNT 2003 if you are free to.

The New Battle Shell truck is a Sterling L7500.

Pictures for comparison: https://static.wikia.nocookie.net/tmnt/images/5/55/Newbattle.jpg/revision/latest- ?cb=20180728053908 and https://jingletruck.com/img/2001-sterling-l7500-box-truck-96-000-miles-5-9-cummins-allison-no-rust-181909304956-0.jpg

The Taxicab is a Checker sedan.

Pictures for comparison: https://upload.wikimedia.org/wikipedia/commons/4/46/Checker_Taxi_Cab.jpg and https://static.wikia.nocookie.net/teenage-mutant-ninja-turtles-2003-series/images/5/50/Turtletaxi1.jpg/revision/latest?cb=20170611015603