Spreadsheet Link in Excel - Context Menu is Missing

I recently installed R2018b on my new laptop which comes with Microsoft 365. Added the excllink.xlam and was able to run run some Matlab functions from my old workbooks. But to my surprise, the context menu was missing and so I needed to always go to the ribbon to send worksheet data to Matlab which really slows down my workflow. I checked the Trust Center settings and confirme that all the check boxes remained unchecked.

Could someone please help? Many thanks in advance!