sent an eevee to evolve into a glaceon through rumbling. after
confirming that i wanted it to evolve it kinda just poofed. checked
the rumble areas section, nothing. not in storage either, also
checked if i released it by accident. dunno where it went, it's
been a few hours and i still cant find it.
oh yeah, and if it's relevant i have 2 explorer bags, but i can
only send out 1 poke for some reason, last time i sent out 2 pokes
for a mission is when i sent out the eevee
Could it be, by any chance, that you sent a Solar Eevee on that
rumble mission? They can't evolve into Glaceon etc, but can be sent
on the mission and get lost after that.
I believe in a situation like this, the best thing to do is make a
post in the Bugs/Complaints section. I hope you manage to get this
fixed and you get your Solar Eevee back!