Tring to Select Domains for Transfer

When on the page to (1. Select Domains) I am getting an API error like below:

API Request Failed: POST /api/v4/accounts/a2bee1961dc4810f2c55xxxxxyyyyaaaaaa/registrar/domains (504)

I’ve removed some of the numbers just in case it’s important.

I’ve tried several browsers, and also two different computers with the same result.

Anyone come across this, I was going to try last week and 100% worked then, but I wanted to see if there was going to be a black Friday deal with the currently registered site of my domains.