PCB Builder cannot recognize file layer count or file types

I have PCB design I a trying to upload and there seems to be some problems with the extension that I haven’t experienced in the past. First (and most importantly), I cannot get the uploader to recognize my design as a 4-layer board. I have tried renaming the gerbers based on the FAQ, but this has no effect. I have tried assigning my 2 inner layers as both “Copper” and “Inner Layer”. Neither of these work. Second, the uploader does not recognize my outline file even if I rename it to .outline as indicated. Soldermask gerbers are also not recognized even though they are named appropriately (.GTS, *.GBS). Even after I reassign these layer to the proper function (outline and soldermask), the quoting page still says that I do not have an outline or soldermask. It seems very buggy and I cannot proceed to order boards even though my design is very simple.

I’m reaching out through private message to further support.