If there's a TT, then I'd suggest getting it snipped immediately, regardless of whether it's considered minor or not. To me it sounds as though there is likely some sort of physiological problem here. Some peads do it, or dentists, or LC may be able to help - you'll need to ask/call around. At this age, I believe it's a quick snip, no anaesthesia, but you'll have to ask them. If you can, maybe also get an experienced LC (or some other health professional with experience in lactation) to check for posterior tongue tie and lip tie, also, to also rule these out.

It's good to bear in mind that even if TT is the issue and you get it snipped, it can take a while for baby to relearn to latch without the tie, so it may not be an immediate fix (but it should get better with time). A skillful LC can help you with this process.

Aside from trying baby-led attachment, you could also consider seeing a chiro or osteo, in case there's some other non-mouth related issue. I don't know if there's anyone near you who has expertise with babies? It's something some mums find useful in these cases.