did you also update update.sh?
line 82: piholeVersion=$(/etc/.pihole/pihole -v -p -c)
line 83: piholeVersionLatest=$(/etc/.pihole/pihole -v -p -l)
line 85: webVersion=$(/etc/.pihole/pihole -v -a -c)
line 86: webVersionLatest=$(/etc/.pihole/pihole -v -a -l)
see also this topic (initially reported here)