Drying filament. Can you go too long/too hot?

I have a spool of Devil Design PETG that ive dried for 8+8 hours (8 hours during the night and 8 hours the next morning when I woke up) at 60*C (which is what the creality drier is set at for PETG). After which i put it in a vacuum bag with color changing silica gel beads.
A few weeks later i noticed the beads changed color drastically indicating they were pulling moisture from the filament, the drier showed 15% humidity at the time i bagged it. The bag was still as tight as it was when i bagged the filament, it didnt look like theres any leaks. The drier instructions say you should dry PETG for 4-8 hours at 60*C, i went double that and it still showed moisture on the beads.

I was wondering are there:
a) issues when drying at higher temperatures but bellow the glass point of a filament?
b) issues when drying for longer than recommended in the drier instructions?

Some people say its fine, others say it ruins your filament and makes it brittle?

Is it changing color because its even lower in humidity than 15%?

The bags im using are food rated and are from what i was told more robust than usual vacuum bags so i presume they cant be pulling in moisture?

Could it be that the color changing silica gel beads are just sensitive to humidity and their color change isnt a good indicator of actual humidity?

Im really confused at this point

The DD filament in question can print quite well even if i leave it out in the open for weeks and weeks, but now that i have more filament for different use cases, that i dont use often, id like to take good care of it to make it last.