After upgrading to Win10 20H2 it still didn't fix my problem even after turning SMB1 Client off and back on. My fix ended up being in the registry for the current user. (On an end-user PC)
HKEY_CURRENT_USER\Network
Deleted the drive letter giving me the problem, rebooted, allowed the network script to re-run upon login.
Interestingly enough, my PC that has build 1909 is missing a registry key that 2004 and 20H2 does have called "UseOptions". Perhaps this may be the culprit and by deleting the entire drive letter from the registry it allowed a clean recreation of the registry
entry.
Unfortunately because the fix appears to be in CURRENT_USER, it may not be a good fix for computers that have multiple users. The fix may have to be performed on all existing user registries.