Am not sure how much switching up style of cotton mask would help, as which people prefer is so personal, but I’m afraid Hot And Sweaty tends to come with most masks (including disposables) - & actually tends to mean they fit. Not wanting to sound rude, but were you wearing them in the really hot spell at all? I’d to change masks when technically there was no need (ie time-wise) one hospital appointment during the heatwave; & the next day when it broke was fine beyond the 4h limit (said mask has a longer limit [if not damp] set by manufacturer due to type of filter it has).
That aside, wonder if the Vistaprint masks might suit you as they’re a different feel to them. (Well, mine is, they’ve now got an integrated filter.) Possibly slightly out there as choices go, but if you want something super basic, there’s a dancewear company that make them from leotard material - they’re incredibly soft & really breathable (while passing the match test).