NitinSharma_jjt0WxE1TG I would suggest you contact Vi, as most above reporting this problem are with Vi. I have personally used 3 providers (O2 UK, Three UK and Vodafone UK) with my 2a, and nothing like this is happening.
As others on Vi are experiencing this, it might be a provider problem. Steps you could take yourself is requesting new APN settings from Vi or turning off Volte/4G calling.
But this seems like a problem with Vi, there is nothing that Nothing can do about it.
