Problem with a Forms field-no forms can be selected

Hello, thank you for creating this plugin. It has been very helpful.

I am posting this message because I am having a problem with a field that is set up as a Forms field on a production website. Last week, when editing a page that was previously working properly, I noticed that a field that is set up to show a Select box with a list of forms created in Gravity Forms to add a form to a page was not working. The problem was that the field heading was rendering, but there was no select box that allowed me to choose a form.

This happened on a site with WordPress 5.5.2 / ACF Pro 5.9.3 / ACF Extended 0.8.7.6 / Gravity Forms 2.4.21.

The same thing was happening on a staging site. I updated ACF Pro and Gravity Forms on the staging site to their latest versions so the setup is WordPress 5.5.2 / ACF Pro 5.9.4 / ACF Extended 0.8.7.6 / Gravity Forms 2.4.22.

After upgrading, the select box renders, but none of the Gravity Forms forms appear in the menu to select.

I created some clean local WordPress installs to see what happens. On these installs, I created a field group with one Forms field and created two simple forms in Gravity Forms.

On a setup with WordPress 5.6 / ACF Pro 5.9.4 / ACF Extended 0.8.7.6 / GF 2.4.22.2, I noticed the select box renders when I edit a page, but no forms appear in the menu to select.

On a setup with WordPress 5.5.2 / ACF Pro 5.9.4 / ACF Extended 0.8.7.6 / GF 2.4.22.2, the same thing happens. The select box renders when I edit a page, but no forms appear in the menu to select.

Is there a setting that I need to adjust to restore the ability to allow me to select from my list of Gravity Forms forms? Thank you for any help you can offer.