My partner and I just combined budgets rather than trying to split everything.
Could you try YNAB together (no extra expense to you and you can offer it free) and use YNAB to split things as mentioned in comment? Or if you don't mind losing some visibility then making a broad "together" expense category to pull from/put into?
Also! Maybe try a different card? Plenty of good cards to try churning! But I agree - it's frustrating when one doesn't pull. My credit unions credit card does that.
Agreed. I wish it was cheaper. Although now with YNAB Together my partner and I can share an account and my sister also agreed to have her budget. (I can technically peek as account manager but I've promised I won't and we're close enough that it's not an issue.) But now it's $30/each!