JOBO 2500 tank edge problem

Hello
I'm asking questions from the first posting. Sorry about that.

I made a big investment lately. I've got CPP2 at home.
There is a problem when developing BW with 2500 tanks.
When I develop a 35mm film, there are long thick mark on edge one side.
The same problem appears repeatedly on every film taken with multiple cameras.
The film is the Rollei RPX 400 bulk film.

I don't think it's about fixing. When I put it back in the fixer, that mark didn't go away.
I'm using Lloyd one for loading bulk film roll, and loader seems no problem. I cannot sea any leakage.

These marks always appear on the outside end of the 2500 reel, far from center core.

I humbly ask for your advice.
thanx.

Dear FerdiAhn,

The problem is a light leak. I cannot say this is the problem but I do have one Jobo 2500 tank that I have to be careful closing. Often the top does not go on evenly. Things improved when I used a different top so the top and tank are now marked to stay together.

Good luck,

Neal Wydra