TeamsApp with multiple tabs do not load in correctly in web "Microsoft 365" app

[MrKSchmitz]

If you create a TeamsApp and have more than 1 static tab, the other tab/s do not load correctly when using the Microsoft 365 app (in the browser).

I've tried creating a boiler-plate app using the Teams toolkit and adding another tab following this documentation.
https://learn.microsoft.com/en-us/microsoftteams/platform/tabs/design/tabs#add-a-tab

I've also tried sample projects listed here:
https://github.com/OfficeDev/Microsoft-Teams-Samples

The tabs work fine in Outlook and in Teams, but selecting the tab header in the Microsoft 365 app seems to fail to create the iframe to load the tab content. Nothing happens and there's no errors in the browser dev console.

The tabs load fine on mobile and with the windows app.

[Nivedipa-MSFT]

@MrKSchmitz - Thank you for your inquiry about your Teams app development issue! Could you please share your manifest zip to test at our end?
Thank you!
Nivedipa
Developer Community Response Team

[MrKSchmitz]

@Nivedipa-MSFT
I've created a git repo that has a sample of an app with multiple tabs working in Teams, but not in Microsoft 365:
https://github.com/MrKSchmitz/TeamsTabsTest

This was created using the Teams Toolkit in VS Code (with some additional cleanup and another tab added).
appPackage.local.zip

The manifest zip is attached

[maglims]

Hi @MrKSchmitz, we are able to repro the issue on Microsoft 365 web, and have filed the bug to the right engineering team and they will prioritize it. Mostly they will get to it early next year. We will update here once we hear an accurate ETA from them. Thanks for the patience and reporting the issue.

[MrKSchmitz]

Thanks @maglims