So, before I start, I have two domains.

The first one is an expired domain that I recently bought. Its sitemap has been showing "Couldn't fetch" in GSC for the past five days.

The second one is a brand-new domain. I submitted its sitemap, and within just 10 seconds, the status changed to "Success."

Both websites are hosted on the same server. I've checked pretty much everything, but I still can't figure out what's wrong or why the first domain's sitemap keeps showing "Couldn't fetch."

So here's my question:

Could this be happening because I bought an expired domain? Is it possible that Google has flagged it as spam or something? I've already checked its history, including the Wayback Machine, and found nothing suspicious.

Does anyone know what might be causing this or how to fix it?

I also tried submitting the same sitemap to Bing Webmaster Tools, and it worked perfectly fine.