Comment 23 for bug 1766217

@rbalint Thanks for looking into this.
I will try to provide the outputs requested when it re-occurs however I'm not sure how they would help - Unfortunately this issue occurs intermittently hence the difficulty in replicating the issue. Upgrades are actually available and upgradeable, just not visible (as per the screen-shots provided by @tommy-trussell).

Meanwhile, you might have some luck referring to @tommy-trussell's output of "apt list --upgradable" above, just in case you missed it...