Can Fenix 7 sapphire solar actually deal with sea water?

After having had a Fenix 5 for many years I treated myself to an upgrade and bought the Fenix 7 Sapphire solar. I am really disappointed with the watch. I am a sea swimmer and a kayaker, but it appears that the Fenix 7, unlinke the Fenix 5, is not suitable for sea swimming: I have had the Fenix 7 for less than a year, and I have already had three replacements because the buttons got stuck after swimming in the sea. Very very disappointing. I do not press buttons under water and always rinse with fresh water after a swim. I also tried soaking in lukewarm water, once the buttons get stuck, but  to no avail.  I wish I could actually swim with my expensive watch, because at the moment I am not, I am using my Fenix 5 for swimming and kayaking. I am also losing my love for Garmin.

Has anyone else experience the same? Or have you got any tips to stop the buttons getting stuck when sea swimming?