The store goes to debug mode by itself

[Carpe_diem]

Hi everyone,

last week I transfered my Prestashop 1.7.7.0 from localhost to a production server. The store works fine, but sometimes it goes to debug mode by itself. I have checked the defines.inc.php file and PS_MODE_DEV_ is set to false. I have cleared all the cache and it doesn't help. I have setup two cron jobs:

- that will rebuild price index

- that will rebuild attribute index

and are those two the problems? 
I have run out of ideas and have searched the forum, but didn't find any solution to my problem. Has anyone experienced something similar and how did you solve it.