I recreated that bug with InDesign 2020 version 188.8.131.525 on my German Windows 10.
Also with InDesign 2021 version 184.108.40.206 on the same machine.
InDesign will crash in the moment I try to apply "align to baseline" in step 7 if the text frame is already anchored:
 Create an new document.  Create an new text frame ( text frame A ).  Create a second textframe ( text frame B ).  Insert some text in text frame B.  Set auto-size of text frame B to height only ( pinned top position ).  Anchor text frame B to text frame B's text.
 Select the text in the anchored text frame B and apply the option "align to baseline".