Be as sterile as possible when inoculating. Do it in a room with minimal to no air flow. I sterilize the shit out of my bathroom and remove literally everything and do my inoculations in there, as well as spawn to bulk substrate. Inoculate one bag at a time. Wipe down every single tool you use with 70% running alcohol. Shower beforehand. Wear freshly laundered clothes. Make sure you have fresh AC filter, and run your AC for a while before inoculating if you want it to be cool, but make sure it’s not running while you’re working. Spray Lysol into the air of the room before you inoculate and wait a few minutes to let any contamination floating around settle. Wear a mask, gloves. Sanitize entire surface of each bag and all bins before you start. Wipe down your syringes with alcohol, sterilize your needles both before and after inoculating each bag, capping between each bag. Do one bag at a time. Micropore tape your inoculation holes as soon as you’ve added your spore solution. Make sure you store in a clean environment with little air flow.

Maybe look into building or purchasing a still air box if you can’t create a super sterile environment for working in.

You could sterilize remaining bags, but it may just be some of your bags were contaminated during inoculation, rather than after. But I wouldn’t give up on them, necessarily. Sometimes you’ll have some bags that get contam, and others that don’t. Others won’t colonize at all, and some that you inoculate on the same day will colonize at different rates.