DNS resolution of shortnames (mostly) broken after I upgraded my EdgeRouter Lite from 1.9.0 to 1.9.1

I think this set of nslookup and ping commands I issued will help explain:

C:\>nslookup apc
Server:  ubnt-home.lab.local
Address:  10.10.1.1

Name:    apc
Address:  10.10.1.3


C:\>nslookup apc.lab.local
Server:  ubnt-home.lab.local
Address:  10.10.1.1

Name:    apc.lab.local
Address:  10.10.1.3


C:\>ping apc
Ping request could not find host apc. Please check the name and try again.

C:\>ping apc.lab.local

Pinging apc.lab.local [10.10.1.3] with 32 bytes of data:
Reply from 10.10.1.3: bytes=32 time=2ms TTL=60
Reply from 10.10.1.3: bytes=32 time=2ms TTL=60
Reply from 10.10.1.3: bytes=32 time=2ms TTL=60
Reply from 10.10.1.3: bytes=32 time=2ms TTL=60

Ping statistics for 10.10.1.3:
    Packets: Sent = 4, Received = 4, Lost = 0 (0% loss),
Approximate round trip times in milli-seconds:
    Minimum = 2ms, Maximum = 2ms, Average = 2ms

C:\>

So the pinging of the shortname fails, the other 3 tests work fine. Roll back to 1.9.0 or 1.8.5, and all 4 commands work fine.

What this new behavior means is that I can no longer get my browser to visit shortnames of devices such as this:

http://apc

it now only works when I use FQDN, which in this example is

http://apc.lab.local

Any ideas? No other changes were made, only a 1.9.0 upgrade to 1.9.1 was done, and everything else appears to still work just fine.