Odd, it if is modem mode then I would have assumed nothing in the VM modem to act as a firewall and bounce pings. I could be wrong though.
First thing I would do is double check your ip address has not changed. (eg https://whatismyipaddress.com/)
Then test pings from elsewhere. https://www.site24x7.com/ping-test.html will do that for you.
That will tell if you general pings are getting through.
Lastly, you could try what I did, reboot the VM hub.
Otherwise, I am out of ideas!

For VM Hub 3.0 you can login to modem page on 192.168.0.1 with password printed on the bottom of your modem. Choosing Advanced settings / Security / Firewall gives you an option to clear Enable tick for IP flood detection and Apply changes. This has made my BQM working again.

That works for router mode but does it work for modem mode? I though in modem mode (192.168.100.1 for login) there was no firewall settings? Or has that changed?

I use router mode so can not check it but maybe worth for you to check it.