Hi @Venkat.Metadata,
It looks like the current limitation for label visibility is set at 400 for both height and width of a visual. So setting at 401 for each will be the smallest sizing you can go while still incorporating the labels.
Unfortunately, there’s not really a work around to get past this limitation, maybe you can include the axis label information within the subtitle so that it always shows up.
As there’s no real work around and I agree this would be a nice option to adjust, I’ll mark this as a feature request to promote visibility to the support team.