Troubled with an expired domain

I recently bought an expired domain with about 354 backlinks, setup on WordPress but alas! started encountering the error "508 insufficient Resource" even after getting in touch with my hosting support. the issue is resolved and after a few hours, the problem reoccurrences again.

The website seems to be well optimized for speed and I have also ruled out issues with plugin and the theme used. I have run out of options, Is there anybody who has ever encountered this more especially with expired domains?

Expire domain isn't the problem. Change your hosting company. I use NameCheap $3/month plan and it works fine for me.

I think this should be your hosting issue or maybe your domain got DDoS attacks.