Does 4G vs 5G matter in India, in the context of IPv4/IPv6 connections?

I use Cisco Anyconnect VPN on my work laptop to access a VM. The VM works on Citrix.

Now, the Login and VM access work fine on my LTE/4g connection in India. However, when I try 5g, the login seems to give me a "Timeout" on my work laptop, and is unable to authenticate.

It feels like the name resolution of work VPN address may not work, or some other reason, I don't know.

But what gets me thinking is for same ISP, same mobile connection, same APN, on LTE the authentication works while on 5g it does not.
Any thoughts as to why? My VM browsing is slow actually currently with LTE only.

PS: I have set the APN to access "IPV4 only" BTW. since that is what I use on wireguard.

@alzhao

Request you to kindly help me. Thanks in advance.

Or, refer me to someone who can help.

So in brief your Cisco Anyconnect does not work on 5G network.

Wireguard does not do anything with this case, right?

For any problem with Anyconnect, it could be due to MTU. Does 5G network has lower MTU than LTE?