404 error in my pages

I’ll explain myself better. I uploaded an offline (localhost) version of a wordpress site I’m trying to build for demonstration purposes, and when you export database (phpMyAdmin) the exported file points to localhost. Then if you want it to work for pastoesdotcom,you need to change in all sql sentences the reference from localhost to https://pastoes.com. Then, if you want it to be in pastoes.free.nf, you need to change all references from pastoes.com to pastoes.free.nf in the database. It’s a little bit tricky, but achievable, The problem arises when uploading pages to pastoes-dot-com, and not when uploading to pastoes.free.nf: page loads sometimes, and sometimes it gives error 404. I’ve been unable to determine the time when that website will work. Sometimes simply responds, and the other 404 error. this is the reason I’m looking for support. I don’t have a fully working version of my website in pastoes-com.