It does sound like an issue that the team should be aware if they are not already. Maybe @joekamprad can weigh in?
It looks pretty valid to me.
error: access denied.
error: no such cryptodisk found.
It is telling you “access denied” immediately after your password entry. Next it is telling you it can’t access your encrypted disk.
If you were to put a stopwatch on “forever” what would it show? 
It does take grub a few seconds to unlock and access a luks partition but without knowing how long you are actually talking about and what your hardware is like it is hard to say if what you are seeing is normal or not.
This is a separate issue and likely one of two things:
- If you windows is installed legacy/bios and your linux is installed efi(or the reverse) grub won’t be able to detect them.
- A recent grub update disabled the detection of other OSes by default so you may need to enable it. The solution for that can be found here.
Interesting. Does that work with the standard EndeavourOS encryption setup? Since EOS uses an encrypted /boot by default grub needs to unlock your encrypted disk before it can even load the initramfs. Does that require an unencrypted /boot or does it work as-is with the default setup?