Hi Kollier B.,
As per your description, please don’t worry we can work together to narrow down and resolve the situation.
It seems you cannot select multiple tabs in Excel online and through Microsoft team via CTRL or Shift clicking.
Based on my test result, it seems I can confirm I also meet same behavior when I open Excel workbook in Excel online version and open Excel workbook in Microsoft Team.
I would like to convey you (first, I humbly request please don’t mind), as Excel web App contains limited features when compared to Excel desktop client applications and in Excel for the web(online) we can't select more than one sheet at a time.
Regarding to your concern, to improve the Excel for web view and this type of change has come up, you brought a brilliant point. We do understand your feeling that it would be very convenient if in Excel for web we can also select multiple sheets as like we select in Excel desktop client app. As we listen to all feedback and consider them for additional feature/future versions of our products, and we requested you send/provide feedback via Excel feedback portal. Your feedback helps us know which features are most important to you.
We can expect this feature to be used in the future in Microsoft Excel for web.
Meanwhile, as a workaround in Excel for web( I request please don’t mind), you may be easy to find the sheet you want. Select the All-Sheets menu, then choose a sheet from the menu to open it. Select a sheet name to open it. Use the arrows just beside the All-Sheets menu to scroll forward and backward through sheets to review ones that aren't currently visible.
I appreciate your understanding and stay safe!!
Best regards
Waqas Muhammad