syntax error with updated plugin ? (+ temporary fix)

Hello. I updated the plugin this morning and my website broke.

I checked my error log and found this :

PHP Parse error: syntax error, unexpected ‘->’ (T_OBJECT_OPERATOR) in XXXXXXXXX/wordpress/wp-content/plugins/acf-rrule-field/fields/class-acf-field-rrule.php on line 711

I edited it myself by changing these two lines :

$new_value[‘start_date’] = $start_date?->format(‘Ymd’);

-> $new_value[‘start_date’] = $start_date ? $start_date->format(‘Ymd’) : null;

$new_value[‘start_time’] = $start_date?->format(‘H:i:s’);

->$new_value[‘start_time’] = $start_date ? $start_date->format(‘H:i:s’) : null;

Now i am good, no more crash, but the next time i update, my change will dissapear. Is this problem due to my config ?

I am in PHP 7.4.30

I am in WordPress 6.3.2

Thanks in advance