Airtel — exclamation mark on my network when i switch on my mobile data

I am using oneplus 7 phone, and have a jio sim and another is airtel, jio works superbly well in my location which is why i put it in sim 1 slot and on the other hand, airtel works pathetic whenever i try to turn on my mobile data i get an exclamation mark on my network sign and nothing works at all after that.