Either your router is set to not respond-to ICMP requests which is highly likely ,
or you have a rule in UFW.
I think the first one is the most likely one.
Best way to test is
then when you do a ping, the above trace will show you the icmp message go out (icmp request) and then one in return,
sudo tcpdump - i any icmp
If you see the first but not the second , the router is not responding.
If you see the first and the second, but ping failing it may be dropped after it is received.
If you see neither, its blocked from going out