404 Page not found when clicking edit page

Good day,

I work as a designer for an agency. I have been working on an website update for a client. However, they also requested that the website be transferred to a new domain name. As I am not a web developer and know nothing of the sort, I asked the hosting company (GoDaddy) to assist with the transfer. After the transfer, everything seemed normal. The current live site was still working fine and I could access the back-end. However, when I went to go an edit a page, I kept getting a 404 Error Page and even when I tried using the Edit with Avada Builder it would just show me a blank screen ( in some cases it shows me a small block in the top left of the footer design). I have been searching for answers, trying everything from resetting the permalinks to deleting the .htaccess file to generate a new one. I asked the GoDaddy support agents to help and they say everything looks normal, and they haven’t responded back yet since.

Could anyone please try to help me as the client really wants to go live with the new updates as soon as possible?