SQL error: Incorrect string value: '\xF0\x9F\x98\x84 \xF0...' for column 'attention_description' at row 1

Getting the following error when trying to update a contribution via "Manage Contribution" (https://www.phpbb.com/customise/db/style/twemoji/manage) :

SQL ERROR

Incorrect string value: '\xF0\x9F\x98\x84 \xF0...' for column 'attention_description' at row 1 [1366]

An SQL error occurred while fetching this page. Please contact the Board Administrator if this problem persists.

Wondering if it's an encoding error due to either an arrow → in the title or copyright symbol © and emojis in the body text; however, the contribution description correctly saved the first time, and scrubbing all non-ASCII characters still doesn't prevent the error on edit.

There are quite a lot of results for Incorrect string value in the other project trackers, but none so far in CUSTDB.