Hi,
When you are using the "place cell" tool, you could use the button [...] to open the "Cell Library" dialog box. You can see all the cell in the list and if you double-click on one of them, the field "Active Cell" is filled whit the cell name in the tool settings dialog. That sounds ok.
Now, when you are using the tool "Pattern Area", "Replace Cell" or any other tool giving access to the "Cell Library" dialog through a [...] button, and you do the same thing (double-click on a cell name in the list), this is the "Active Cell" in the tool "Place Cell" which is filled (and this tool is started).
In my opinion, when the dialog "Cell Library" is opened by using a button [...], this dialog must received the information on which tool has started it to fill the right field accordingly.
See the video hereafter showing the use of "Replace Cell" than select [...] which open the dialog "Cell Library". After double-clicking a cell name in the list, the tool "Place Cell" has been started and the "Active Cell" is filled instead "Use Active Cell" in the "Replace Cell" tool.
[View:/cfs-file/__key/telligent-ideas/9f5cf279-12ec-4854-adae-c775687342d4/2020_2D00_04_2D00_01_5F00_11h48_5F00_51.mp4:320:240]
Thanks,

Philippe