Certificate prompt at Admin login

Hi,

After upgrading the FGT100F from 7.2.10 to 7.2.11 we are now seeing a user certificate prompt each time we attempt to connect to the admin interface for the 7.2.11 firewalls.

I found the below article and  run the following two commands, it appears we have already met those conditions.
FGT100F # show full-configuration | grep admin-https-pki-required
set admin-https-pki-required disable

FGT100F # show user peer
config user peer
end

Certificate prompt on Admin interface - Fortinet Community

It looks like we had the same issue as for v7.4.6 and v7.6.2 but the article states it is currently under investigation. 

I checked as well the upgrade path for FGT100F and it seemed upgrading to 7.4.8 and 7.6.3 is not an option for the fixed version.

For your advise. TIA :)