after reading a lot I found out it has to do with the cache… I deleted everything inside wordpress and nothing happened, so I kept reading and found out that there’s LiteSpeed Web Cache installed in the whole server, I asked the hosting company to help me out and they did, this is what was causing it:

“this issue was caused by the blocking of the rule by our Modsec apache module. We need to use this for security reasons. The module is configured to protect web applications from various attacks. ModSecurity supports a flexible rule engine to perform both simple and complex operations. I have fixed this issue for you. Please check it from your side and let me know if this occurs again.
Also, here you can find the article about the Modsec module:
https://www.namecheap.com/support/knowledgebase/article.aspx/9542/22/what-is-modsecurity-and-why-do-we-need-it/.”

I’m on debug mode and yes it’s a related problem
the console says
When inserting images: POST https://mysite.com/wp-admin/admin-ajax.php 403
when adding js: POST https://mysite.com/wp-admin/admin-ajax.php?td_theme_name=Newspaper&v=11.3.2 403
send @ load-scripts.php?c=1…p-hooks&ver=5.8.2:2
ajax @ load-scripts.php?c=1…p-hooks&ver=5.8.2:2
s.ajax.s.ajax @ load-scripts.php?c=1…p-hooks&ver=5.8.2:5
(anonymous) @ td_wp_admin.min.js?ver=11.3.2:65
dispatch @ load-scripts.php?c=1…p-hooks&ver=5.8.2:2
v.handle @ load-scripts.php?c=1…p-hooks&ver=5.8.2:2

I’ve changed the permissions in the “admin-ajax.php” file even to 777 and I’m stuck.