have a lot of errors on my website

1. The "ADD" button in the Field-bound Boxes it's invisible
2. The Testimonials display the error message
3. Multifield Location Filter the "Add an Entry " button invisible
4. The "ADD" button of the listings box it's invisible
5. MySQL ERROR when creating a new user account by admin or super admin
I don't know why.

error link for a Testimonial
https://www.estateposter.com/about-us.html

I don't know how these problems arise. Even though I didn't edit or write any code. But there has been a dramatic shift on my website. And it greatly affected my website settings. I'm extremely worried. And I'm afraid these problems will happen again when my customers use the website.

yesterday I had a problem with the limited admin access Flynax support helped me to fix it, but after that what functions about the item box that I give to limited admin, it's can not be used by another admin including the super admin because the "ADD" button it's invisible only limited admin that I give permission (anchalita) can use it, I create a new admin and give the same permission but all admin can't use it.

I think these problems may be related to the PHP version. I tried installing the script in a different PHP version. It found that some problems disappeared such as the Testimonials issue. When I backed up my data and switched to PHP version 7.4, I did not experience this issue. But at the same time, other problems arose instead. Please help me to fix it.

Field-bound Boxes error.png
TESTIMONIALS error.png
Multifield Location Filter error.png
add new account error.jpg