it's their nodes and not charging a fee at all.
sometimes my lightning tx's go through immediately or within 2-3 minutes, then other times to the same wallet(s) it pends for hours or days then ultimately fails or sometimes goes through.
it's inconsistent as fuck because they're not charging routing fees to route our tx's. This causes our tx's to only be able to go through channels and nodes that are feeless...so it's difficult to find a route sometimes.