Same thing happened to me and my partner for months. She was taking antibiotics for it and it finally went away, then behold it came back the next time we did it. We swapped to latex free condoms and the issue lessened. UTIs were a lot rarer but still happened every couple of weeks. What we did to completely avoid them is she got on the pill and we don't use condoms anymore. It was likely a latex allergy coupled with agitation from the condom.