After upgrading from free to m10 server my app is not working

I’m a non tech founder and I’m asking for urgent help!
Yesterday, I just upgraded my free mongo db account to dedicated m10 but as soon as my upgradation was complete my app signup/login stopped working.
But my database is working like I can see the users signing up in the document but they in the app they can’t login or signup.

Do I need to make some changes in my backend? or is it something else I need to do

Hello @ajay_singh4,

Welcome to The MongoDB Community Forums! :wave:

It seems like you are facing a similar issue mentioned in this thread. Could you check if the solution provided in that thread solves your issue?