Incorrect integer value: '' for column `J4PRD_jem_events`.`unregistra_until` at

When editing an event I got a message:
Incorrect integer value: '' for column `md290db332639`.`J4PRD_jem_events`.`unregistera_until` at row 1

No registration is enabled for the event in question, so (I think) a 0 value should be set in the record.
Apparently the value '' was seen as a string instead of a null value, so an attempt was made to register not the default 0 but the ''.

For the sake of clarity, when creating the event, the record is filled correctly (ie with a value of 0), this error only occurs when changing the event.

Facts:
Joomla: 4.3.3
Joomla Language: Dutch (but error also occurs in UK English)
JEM: 4.0.0
PHP: 8.2

Because registration is not used now, I temporarily converted the field type to VARCHAR as a workaround, so users can now save changes to regular events.

In another topic the following SQLsolution (via PHPAdmin ) was given for this problem.

ALTER TABLE `xxxxx_jem_events` ADD `unregistra_until` int(11) NOT NULL DEFAULT 0 AFTER `unregistra`;

Johan.