Peplink 30 admin not working after upgrade to 8.1.3

After upgrading my Balance 30 firmware to 8.1.3 the address is unresponsive. Everything else is working and I have internet access as before. My computer gets an address in the 192.168.1.x range. I have tried with Chrome, Explorer and Edge.
I tried to reset the router but the reset button does nothing, even after 90 seconds.
In short: everything is working as before except that I can not manage it anymore. ¿Any suggerstion?

I unplugged the router for 10 minutes and plug it again. The reset button is still not working but the address is now working as before.