Correct passwords keep appearing as incorrect

I don't know why passwords are not working... Every time a user registers on my website, their accounts are verified easily but the same passwords they use to register appear as incorrect.

I have disabled my cache plugin and it doesn't matter whether they register from udija.com/login or udija.com/my-account... The passwords still appear as incorrect and I don't know why

If Users reset passwords it works but initial passwords used for registration don't work at all

I'm fed up at this point