Dynamic data connectivity with 3rd party web parts not working

Target SharePoint environment

SharePoint Online

What SharePoint development model, framework, SDK or API is this about?

💥 SharePoint Framework

Developer environment

None

What browser(s) / client(s) have you tested

• 💥 Internet Explorer
• 💥 Microsoft Edge
• 💥 Google Chrome
• 💥 FireFox
• 💥 Safari
• mobile (iOS/iPadOS)
• mobile (Android)
• not applicable
• other (enter in the "Additional environment details" area below)

Additional environment details

• browser version
• SPFx version
• Node.js version
• etc

Describe the bug / error

When setting up dynamic data connections between 3rd party web part and SharePoint list web part, the drop-down which used to show all the SharePoint web parts on the page is not working and doesn't list all the SharePoint web parts. This used to work in the past. Our customers are complaining that this is breaking their workflows. Please look into this.

Steps to reproduce

1.Add a 3rd party web part and add a SharePoint list web part
2. Set up dynamic data connections between the two web parts
3. Open the drop-down to select the SharePoint list web part
4. Observe the drop-down does not list the SharePoint list web part.

Expected behavior

Drop-down which calls the SPFx dynamic data API should list the SharePoint list web part in the drop-down.