Hi Peter,
When changing the PHP version from 7.x to 8.x on a J3 website using Articles Field, I get the following error in the front-end (only on the pages calling that Custom Field of course)
implode(): Argument #2 ($array) must be of type ?array, string given
() JROOT/plugins/fields/articles/helper.php:108
So on that line 108, I changed
$value = implode($value, ' ');
into
$value = implode(' ', $value);
and it fixes the issue.
So I guess you want to update Articles Field to make it PHP8 compatible.
Txs