What issues would arise if I decide to move my local network to IPv6?

I am managing a small corporate network, and actively investigate the possibility of getting rid of IPv4 entirely, at least on the LAN level. I intend to disable IPv4 DHCP and connect to each machine using their IPv6 addresses.

All of my devices support IPv6. My ISP is currently running dual stack (IPv4 + IPv6). What issues would arise if I decide to move my local network to IPv6?

Here are my efforts so far:

  1. I bought a static IP address (fyi it costs additional money in my country) and my ISP gave me a static IPv4 one. My public IPv6 address still changes after a router reboot. I asked for a static v6 address but the technical support couldn’t help. They said they were running IPv6 on top of IPv4 or something like that.
  2. If I change the WAN connection in my router from the default IPv4 + IPv6 to IPv4 only, it works. But if I set it to IPv6 only, I cannot connect to the Internet. I don’t know why yet.
  3. By disabling IPv4 support from Windows Network Adapter Properties, web browsers start looking for AAAA DNS records. Most websites still use A record, and do not have AAAA record (maybe because they don’t have static IPv6 address for it). The web browser cannot fall back to IPv4 option, and the domain names cannot be resolved.

Is it practical to use IPv6 exclusively on LAN as of now?