Site goes down – Newspaper theme issue?

Hi,
We have been facing a peculiar issue since the last 6-8 months. We asked on various other forums/wordpress and few people said it is to do with your theme

https://prnt.sc/1qd42pc

We get 504 error for 5-15 mins randomly and then the site comes back up. What could be the issue?
We checked DNS maps too, that is fine.

Stunning thing is we found nothing in the error logs. Because of this, we moved the server from Godaddy to Digital Ocean as well (VPS) and still the issue continues, hence people are saying it is a theme problem. Am not sure, can anyone help?

Website: http://www.gadgetbridge.com

We checked error logs:
2021-08-20 16:53:15 Warning 162.158.74.140 AH01071: Got error ‘PHP message: PHP Warning: is_readable(): open_basedir restriction in effect. File(/Newspaper/theme.json) is not within the allowed path(s): (/var/www/vhosts/gadgetbridge.com/:/tmp/) in /var/www/vhosts/gadgetbridge.com/httpdocs/wp-includes/class-wp-theme-json-resolver.php on line 354’
2021-08-20 16:53:19 Warning 162.158.74.94 AH01071: Got error ‘PHP message: PHP Warning: is_readable(): open_basedir restriction in effect. File(/Newspaper/theme.json) is not within the allowed path(s): (/var/www/vhosts/gadgetbridge.com/:/tmp/) in /var/www/vhosts/gadgetbridge.com/httpdocs/wp-includes/class-wp-theme-json-resolver.php on line 354’

Keep getting this error.