Visualize sporadic data for large dataset

I am trying to visualize a metric in a time series, that only records problems for 10K items.
A table of 10k rows is not useful.
99% of the time fewer than 10 items have an issue concurrently
A specific item may have flapping errors, on-and-off, over a short time range, but others will be chronically in error.

What is the best method of visualizing this?

The closest thing I have seen is like a Gantt chart, except a line on a row may be discontinuous.
Let x-axes show time
Let y-axes split vertically by record label ‘Location’ (each on their own level)
The line for a ‘Location’ will be segmented as the item falls in and out of an error state

Has anyone tackled this kind of situation?

I would go with 2 visuals. one for general the other for the frequent offenders so that they don’t get lost in the chatter?