I had the same issue after a sudo apt upgrade to the latest packages.
After an earlier upgrade I always had to type in my password twice at boot because of this issue. After fiddling with cryptsetup and trying to fix things I just reinstalled pureos and did not update anything.
So far I have no further issues except for many halted updates.
I would be happy if someone knows how to properly fix this.
Also related:
Decrypt prompt disappeared after update
New Librem 13v3 Won’t boot to disk login