I struggled with razor bumps when I shaved with cope multi blade razors, like gillete razors any of that shit.
Razor bumps are incredibly subhuman but thankfully its easy to fix. Switch to single blade safety razors like this.
Now it doesnt really fucking matter which dropshipped brand you get, i just put a picture so you know what im talking about. Keyword search "single blade safety razor" into amazon and get the cheapest one.
The reasoning for this being meta is because it doesnt take the hair follicle down as much, so it wont grow underneath the skin. It still gives you a clean shave but you can tell at an extremely close distance in the mirror, it doesnt cut the hair as much.
https://www.youtube.com/watch?v=QiJe2t_fO0w&ab_channel=TATARARazors
video example of why the bumps occur.
For some reason I still deal with some irritation on my neck even with this razor, its much better than a multi blade but still some redness. I was able to totally remove all irritation by using an electric razor on my neck. I chose this one
It isnt gonna allow u to get a clean shave on your face but for your neck thats shadowed, it gets the job done enough. Its better to not have as close of a shave but 0 bumps on your neck since you cant see your neck hairs. I also use it on my mandible since for some reason I get bumps there, weirdly only on the right side of my jaw. If you have specific spots you get bumps just use this tool on that surface.
I would also use this if you let your beard grow out for a bit, to take the hair closer down to your skin then finish it off with your single blade. The reason shaving with a razor is worth it aswell, is because it exfoliates the skin extremely well.
The final option which is a bit more pricy is IPL lasers from medspas. This lasts about 3 months and is a few hundred bucks. Its good if you are lazy and dont wanna shave daily but its less economically efficient.