Sounds potentially like Mast Cell Activation Syndrome (MCAS). It’s a co-morbidity of EDS and presents differently in everyone. I had this issue with any deodorant I tried, even ones that were marketed as natural! The plain arm & hammer deodorant and the hypoallergenic Native deodorant helped heal my underarms from these spots and scarring. I would try a few that have clean, natural or limited ingredients (you can use the ThinkDirty app to find out the toxicity level of your current deodorant and help find a better fit). You may need to go without deodorant for a few days or simply cleanse with baking soda and see if that helps to clear it up. If nothing resolves after a week, it’s probably best to see a dermatologist and find out if something else is going on.