LaviVaswani

Recently in some areas suddenly ! appear on the network tower in my phone and internet not work after that. I tried many options but nothing work for my Nothing phone 2(a) then I changed my preferred network to 4g and now internet is working Properly but I can’t use 5g now. Is this a common issue with others also because the phone should be capable to switch between 5g and 4g as per requirement or it is the issue related to jio sim which I am using in India. Please solve this issue with update or if possible now guide me how to use 5g without ! Mark and repeated connection errors.