Comment 3 for bug 1751120

Dan Watkins, thank you for reporting this and helping make Ubuntu better.

1) Is this something that started to happen after an update? If so, which specifically?

2) After the freeze, are there crash files in /var/crash?

3) As per your logs, you are using kernel 4.13.x (not supported in Ubuntu 18.04). Hence, if you restore your kernel to a supported version (4.15.x) is this still reproducible?