[SQL] How to search table for special characters excluding some Hungarian letters?

I want to return all rows containing any other character than letters, numbers and space, but I also want to whitelist Hungarian letters. However when I run the following script:

SELECT
*
FROM
table T
WHERE
T.columnname REGEXP '[^a-zA-Z0-9 áéíóöőúüű]';


It gives this error:

SQL Error (1267): Illegal mix of collations (latin1_swedish_ci,IMPLICIT) and (utf8mb4_general_ci,COERCIBLE) for operation 'regexp'
​

What's the correct way to do this?

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