Can you give the below a go and see if that reverts you to a working version?
cd /etc/.pihole
sudo git checkout v3.2.1
cd /var/www/html/admin
sudo git checkout v3.2.1
pihole -r
pihole checkout ftl v2.13.2
Can you give the below a go and see if that reverts you to a working version?
cd /etc/.pihole
sudo git checkout v3.2.1
cd /var/www/html/admin
sudo git checkout v3.2.1
pihole -r
pihole checkout ftl v2.13.2