I have two Vado IHG 5.0 with the same issue.
While charging I can’t turn on any of the bikes to check the battery level.
If I unplug the cable then there is no problem.
When I purchased the bikes I do not recall this problem.
Any thoughts or is it just me?
That is not a problem. My bikes, different makes, do that as well. There's probably a technical (i.e. electrical) reason for it. Nothing to be concerned about.