"Connected" to the VPN, but not workig

Hi everyone
I have installed a raspberry with pivpn in my parents house and I can connect with my mobile and pc but the only way to connect with my AR300M is if I connect to my mobile with tethering, never with my home router: apparently is connected but cannot reach the other net

Should use the default port 1194? I have read something about change the MTU, but I can’t find where on my MitraStar router….
Any idea please?

Do you want to access the server’s LAN side?

Hi Kyson-lok,
The point is that despite I’m connected to the VPN (apparently) I can not ping my parents computer, while I can if I’m connected from android or if I use the tethering of my phone with the AR300M.
It’s very strange!

Could you please take a screenshot of the OpenVPN status page?