I'm experiencing a bug where Nested Line Styles are interfering with Grep Styles.

To reproduce:
1. Create a Character Style "Small Caps" that only applies OpenType All Small Caps.
2. Create a Character Style "No Break" that only applies the No Break rule.
3. Create a Paragraph Style "Test":
    a. In Nested Styles, add Small Caps for 1 line
    b. In Grep Styles, add:
        i. Small Caps: ([\u\d&@#\$%/]{2,}(?!\l{2,}))|([\d&@#$%]+)|(I'D)
        ii. No Break: (?<=.{55}).{15}$
4. Fill with placeholder text, and add a string of capital letters (something that matched the Small Caps grep) somewhere in the middle

You'll notice that the line style and grep small caps work, but the No Break style isn't being applied. Switch the order of the grep styles (No Break first) and now it's the opposite—No Break works but not Small Caps.

Now, remove the Line Style, and suddenly both grep styles work.

Refer to the attached screen shot. I can also provide a sample .indd file with the styles prepared. I've used styles set up like this for a while without problems, so this may be related to a recent InDesign update.

Hi, InDesign team.

I've run into a serious bug with GREP styles. Any GREP expression containing an ampersand character that is entered as a GREP style in a paragraph style will suddenly acquire additional ampersands whenever I scroll through the list of GREP styles.

STEPS TO REPRODUCE:

Create a simple GREP style as part of a paragraph style.
The entire GREP expression should consist of the single character &. (Though this also happens when the & is part of longer expressions.)
Make enough other GREP styles that you need to scroll in the window to see them all.
Close the paragraph style window and reopen it.
Scroll through the list of GREP styles.
When you scroll, you will see that "&" has become "&&."

HERE ARE OTHER DESCRIPTIONS OF THIS ISSUE:

https://community.adobe.com/t5/indesign/ampersand-gets-doubled-in-grep-style/td-p/10329693?page=1

https://community.adobe.com/t5/indesign/self-propagating-ampersands-in-grep-in-a-paragragh-style/td-p/5881764?page=1

https://indesign.uservoice.com/forums/601180-adobe-indesign-bugs/suggestions/36196819-paragraph-style-grep-functions-are-unreliable

I believe I have gotten around the bug by using the Unicode value for an ampersand, but this is not ideal. I need to be able to trust that the GREP style implementation is solid.

Thank you.