After move to different domain, ERR_TOO_MANY_REDIRECTS and not entering in DB

[abcschooldr]

I changed my store's domain name. It was moved from abcrealestateschools.com to abcrealestateschool.com because google was throwing a phishing error.

Example: https://www.abcrealestateschool.com/ABCOrderForm/
Broker Package: 18-hr Nevada Law & Broker MGMT Combo ONLINE-ONLY
Add this to my cart

It says - This page isn’t working www.abcrealestateschool.com redirected you too many times. ERR_TOO_MANY_REDIRECTS
It also isn't entering the order into both the database and the store.
Someone was recently able to order - money went to PayPal, comfirmation email worked, no order to database or store.
I can't get it to work. My host says it works for them except for missing images.
Using Fast and Easy checkout. PHP 5.6.40 PHP version: 7.3.27
My host moved it.
I used the developer's tool kit to see if there were any files that still used the old domain, but it couldn't find any.
Are there files that I need to change?

In its previous configuration, SSL didn't start until the entering of information on the order form. https://www.abcrealestateschools.com/ABCOrderForm/ In other works, the home page didn't have SSL, the product page didn't have SSL. It wasn't until the index.php?main_page=no_account (the Billing Information page) that the SSL kicked in. I wonder if that was 'by design' and it will error if SSL starts on the home page of the Zen-cart. The reason that I don't have SSL over the whole site is that I also have a 'moodle' course management system on the site that will crash with SSL on the log-in page.
Any help is appreciated.

[abcschooldr]

Seems like I found the cure. My host is Siteground. I read in another post about caching. Because I couldn't make pages change, I clicked on speed-caching-NGINX DIRECT DELIVERY and turned it off. That didn't fix the problem. I also needed to flush the cache with DYNAMIC CACHE. That fixed the problem. My admin wasn't updating and ERR_TOO_MANY_REDIRECTS was randum but frequent.
If the site monitor wants to delete my post, do it. If you think it is useful, good.

[DrByte]

Ya, Siteground's new cache that they forced on everyone does have plenty of side-effects.