OneRNG not working after reinstalling onerng_3.6-1_all.deb

[Mark]

I have been using OneRNG with Linux Mint 19.1 for some time. Today, after reinstalling Mint I plugged in my OneRNG which lit up as expected but I had forgotten to reinstall onerng_3.6-1_all.deb. After removing the OneRNG and installing onerng_3.6-1_all.deb, the LED on the device lights up briefly after I plug it in but then turns off. Running cat /dev/random (which would normally dim a light that it on) has no effect on the unilluminated LED.

Can anyone suggest what might be wrong and what I should check, please.
Mark