Problem with Qgis 3.x, rotated labels flip horizontal

[dquinton]

Using Qgis 2.x I used Easy custom labeling plugin in order to have better control of label positions.

In Qgis 3.x it looks like this plugin is not entirely needed any more as Qgis now has the same tools on toolbar.

But, I do still have a lot of label layers made with this plugin, with 100's of labels all positioned by hand with lots rotated. Which means I need to still open those projects and expect to use the plugin to make adjustments to labels.

But a problem occurs. When I want to rotate a label, made with the plugin, I now get a box asking what Key I want to use to store the data. Well, whichever one I try, when I then try to rotate just one label, all the labels of the layer flip horizontal.

Reproduce:
adjust a label from a layer made previously with EasyCustomLabeling plugin, using Qgis 3.x, and all its labels flip horizontal.

edit layer > rotate tool > click label > select labelField > rotate label (all turn horizontal)

So how can I continue with layers made with the plugin, layers which total thousands of labels?

can I copy data from the attribute table into the vector layer holding the data the label layer was made from?

Thanks