Hi @Raymond
Welcome to Q&A forum ~
Based on my research, your issue needs the VBA code help, but we are primarily responsible for general issues of Office.
To help you better, I would add the related tag. Thanks for your understandings.
Then here are 2 threads I found, "Last item in multiselect listbox only partly visible", "Excel ActiveX ListBox Shrinks with each update".
According to the threads above, there is a Listbox Property called IntegralHeight whose default property is True that something to do with screen resolution and optimal display of listbox contents. Please set that to False to have a check.
Besides, we can't run VBA code in Excel for the web, if there is a solution for this VBA code, the users need to download the workbook and open it with the desktop client.
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