Error on membership Sugn-up: Column 'lastResetTime' cannot be null

Hi,
I'm getting "Column 'lastResetTime' cannot be null" on new membership sign-up.

I recently migrated my site from J3 to J4 and finally to J5.3.0 - all went smoothly

CB/CBsubs are up to date, as are all other plugins and components.

I ran all the CB database Tools - no errors

I checked System - Maintenance - Databases - Update Structures (no errors reported)

I attach a copy of my System Information

Any help would be appreciated,

     Phil.