numerous keys stopped working

My Macbook keyboard has suddenly started having problems. the “enter” key, the ‘p’, and the numbers don’t respond at all. the ‘=’ key works but also adjusts the keyboard backlight for some reason. mouse keys are not enabled. any ideas of what could cause this short of replacing keyboard. i had been in a humid area for several days and it worked fine there but wasn’t working when i got home

there are possibly other keys i haven't realized yet are not functioning or functioning improperly but those are what i've noticed