Mates condom vs Skyn condom

My partner is allergic to latex and Skyn produce the only non-latex condoms on the market. For me, they are smooth and feel great. They are more comfortable than latex and arguably feel even better than without a condom. However, for my partner, they feel fine for about 10-15 minutes before they start to produce a vacuum and squeeze down hard, causing him pain and obviously ruining the moment. We are not sure if this is a sizing issue or something else. There aren't any further size options or otherwise for us to try so we are limited to very uncomfortable safe sex for him, or using the withdrawal method instead which has its own problems.

Opted for latex free. So easy to use, protects against STI, it’s a no brainer for me. Just as pleasurable

Other condoms can give my thrush or cystitis so I assume I must have a mild latex allergy. These condoms are amazing they fit great and they feel like nothing, I hardly notice them at all. And 0 side effects! Just have to drain the purse a little bit instead