Need help with my new seedlings! Sunken/watery spots

[Orchidreamer]

This is my first time growing seedlings from flask. They are Den harveyanum seedlings that were just deflasked, and they were perfectly healthy seedlings with perfect leaves when I got them. I potted them up in sphag last night, 3-4 plants to a pot, and placed the pots in ziploc bags with the tops slightly open. I sprayed with diluted physan.

Now, 24 hours later, I notice some of the leaves have gone bad! Some of the leaves look watery, as if they're bruised, while others are pitted/sunken, and some of the pitted areas have turned dark. I cut off all the bad portions and dabbed with cinnamon.

The watery bruising reminds me of erwinia or soft rot...what do you think? I made sure to disinfect everything and keep everything clean though. The sunken pitting reminds of mesophyll cell collapse due to cold damage...but the seedlings have not been cold and I have them on a heat mat (65F room temp + 10-15F extra heat).

Should I use stronger fungicides?
Pic 1: before potting up
Pic 2: potted up
Pic 3: I had just been doing leaf surgery 10 min ago.