Trigger failure AFTER UPDATE on MariaDB - sql

Question

I am trying to automate some tasks within a DB rather than in the app. We have a small MariaDB for tickets to be sold. When a ticket is sold, its status needs to be set to NOT_VALID until payment is made. After payment is made, the ticket needs to be set to VALID. The invoice itself is in a table 'som_accounting' and with a reference table (som_accountingtickets - because of lazy design decisions) it points to the tickets. Now I am trying to automate that the flag in the ticket table is set to VALID when the PAYMENTSTATUS column in the accounting table changes from OPEN (1) to PAYED (3).
When I use this on the console (dbeaver or terminal) it works fine:
UPDATE som_ticket SET ID_ticketstatus = 4, activation_date = CURRENT_DATE()
WHERE ticketID IN
(SELECT act.ID_ticket FROM som_accountingticket act
INNER JOIN (SELECT * FROM som_accounting) AS ac
ON ac.accountingID = act.ID_accounting
INNER JOIN (SELECT * FROM som_ticket) AS t2
ON t2.ticketID = act.ID_ticket AND t2.ID_ticketstatus = '1'
WHERE act.ID_accounting = '565');
Now I put this into a trigger an I got an error:
CREATE DEFINER=`<user>`#`%` TRIGGER `somt_au_accounting`
AFTER UPDATE
ON `som_accounting`
FOR EACH ROW BEGIN
IF NEW.ID_paymentstatus = 3 AND OLD.ID_paymentstatus = 1 THEN
UPDATE som_ticket SET ID_ticketstatus = '4',
activation_date = CURRENT_DATE()
WHERE ticketID IN
(SELECT act.ID_ticket FROM som_accountingticket act
INNER JOIN (SELECT * FROM som_accounting) AS ac
ON ac.accountingID = act.ID_accounting
INNER JOIN (SELECT * FROM som_ticket) AS t2
ON t2.ticketID = act.ID_ticket
AND t2.ID_ticketstatus = '1'
WHERE act.ID_accounting = OLD.accountingID);
END IF;
END
Database reports this:
Error synchronizing data with database
Reason:
SQL-Fehler [08]: (conn:3) Could not read resultset: unexpected end of stream, read 0 bytes from 4
Query is: UPDATE d0294220.som_accounting
SET ID_paymentstatus=?
WHERE accountingID=?, parameters [3,568]
Why did it run well in the console but not in the trigger?
MariaDB 10.5.8