Well done, playing with databases can often present problems. Is it SQL?
Yes it is SQL (MariaDB)
Actually for the technically minded it wasn't the SQL database that was the problem but a conflict of PHP parameters in which the session variable was allocated to 3 different directories 2 of which did not even exist. Once that was resolved the program (PHP) that performed the update of the database functioned. I was on the verge of performing a long list of SQL queries by hand but fortunately I discovered the real problem in time.
It only took 2 weeks to find it 😡
