Labels mixed in calculated fields

Guys,
Since several versions ago (can’t remeber exactly, must be since around v11) I get mixups in the labels of calculated elements. Data source is influxdb v1.8.3.
Example:

Result:

What has changed? What am I doing wrong?
The label of the right-most box should read as PV1 only, but not as PV1 e3dc.max.

Another, and similar strange example:

A warning appears and the label gets mixed-up in another way.

This is independant of the used visulisation, be it time series, stats or else.
Any help is appreciated.

Cheers and thx.

Not sure why it happens, but as a workaround you may use Organize fields by name transformation and specify the name you would like to see:

Thank you for the hint.
However, this tranformation does not seem to be bugfree, too.

a) it complains about the nb of frames, if more than one is visible

b) it works somehow nonetheless. After entering xxx as a substitute, the label disappears completely.

But, surprise, when making the other frames visible again, the replaced label is there.

Any further insights from anybody to the original issue?

Before applying Organize fields you can apply Join by field transformation to have a single frame.

Right. But.
The example I gave was simplified; my real use cases are way more complex; just to give you a glimpse


Labels are simply wrong…

Looks like no more insights…
What is your experience / best practice? Open an issue? And where?