My wifi keeps disconnecting when i use vpn

Consider more secure wifi configuration.

Change your router’s WiFi to use WPA2-AES (CCMP) with no WPA or TKIP. Updating this setting ensures that your devices always connect in one encryption mode

1. TKIP is obsolete and not considered secure. Choose WPA2, the latest encryption standard, with AES encryption for optimal security
2. If your router doesn’t specify TKIP or AES, the WPA2 option probably uses AES

Why are you using a VPN?

If you're not using it to connect to your employer's secure network, there's no point.

So-called public VPN services are nothing more than glorified proxy servers that will do more to compromise your privacy and security than they will to protect it.