I have been prone to processing errors for quite some time and due to the cost of these errors adding up I stopped LF BW photography all together until I found the source of my problem. This means a lot of reading. Recently I had an e-mail conversation with a getleman who suggested the issue could be my choice of developer and developing process.
I use Efke PL100 in homemade BTZS tubes and Pyrocat HD. He suggested this was a bad combination.
I thought I would ask here to see if anyone else has had this issue?