I am facing problem regarding connection between my node js web app and mongodb atlas cluster

I am facing a problem with my mongodb cluster, earlier i connected my node js express application with my mongodb atlas cluster and it was not working (I am assuming this is the error from the mongodb atlas cluster because when i changed the mongodb connection string to the localhost of mongodb, it was fine), the browser shows behaviour like –
1- the reeload button is busy, but nothing happens
2- no error in the console and mongodb atlas has been connected fine
3- I can access pages like login(where there is no mongodb query present in the backend), but when I connect other pages, it is showing no responce
4-I then descarded that cluster and made another one, then it worked fine

but the issue is that, the newly made cluster has also shown this behaviour when connecting with my localhost today, it was working fine till yesterday, it is running fine when connecting with my hosted website though, I have cross-checked my connection string several times

I would be happy if anyone has a clue about this

cross-checked ip address and connection string several times, no error is showing in the console
(btw, I hosted my site in aws)