Can't make a selection in a text block.

[notarobotatall]

I can't make a selection in a text block. Either the whole block is active or nothing at all.
Even in the newest Publisher beta it is not possible to select a single word.
The blue selection bars are only visible if I select the whole text.
iMac, 5K, 27 inch 2017, High Sierra

[carl123]

Are you using Filler Text?

If so Right-Click the text and select Expand Field

or Text > Expand > Expand Field