Unable to update wordpress post content due to WAF blocking POST requests to /wp-json endpoint

Hello everyone,

I’m trying to create a cybersecurity blog on wordpress but I’m having problems whenever i try to update my blog post with some specific words. To be more precise I get a 403 forbidden and this is due to the fact that the WAF is blocking my requests.

For example if I try to write /etc/passw+ with letter “d” instead of “+” I get blocked, while omitting the “d” I don’t face any problem.
In order to solve the issue I tryed to set WAF bypass rules for my IP address and for my domain but it didn’t work.

I also lowered the security level to the lowest possible for the free plan.
The problem is really similar to this one “Updating failed. The response is not a valid JSON response” - #9 by user3346.

How could I solve?

Thanks in advance