Bulleted List Format Disappearing

I posted something the other day and thought I had resolved the issue, but it is still occurring and I am not sure how to handle it.

I am concatenating a list of text into a bulleted list, then combining those lists into an email template. I want the final text to be editable before sending, so I am using a button to dump the formula results into a text field for editing.

When I do so, the text appears as a bulleted list, but when I click into the cell, the formatting goes away.

I am not sure if this is a bug or a result of me not grasping something technical about the action of creating the text, but I could use some help troubleshooting.

Below is a Loom of what I am seeing:

Also worth noting, the formatting menu appears greyed out when I first click on the text.

I wonder if this is at all related to this bug.