Pasting from cells into Outlook NOT keeping source formatting

I’m going to do my best to explain this in a way that makes sense:

For work, I have an Excel spreadsheet containing all the templates of the emails I send most frequently. Normally, I double-click into the appropriate cell, CTRL-A, CTRL-C, and then go over to Outlook and CTRL-V into an email. Normally, this keeps the source formatting, but as of yesterday morning (March 26, 2026) it isn’t. Now I have to manually add all the bolded and underlined sections to every email and though it seems small, I can’t stress enough how much it’s thrown off my workflow.

I CAN single-click the cell, CTRL-C, and CTRL-V the entire thing, border and all, into Outlook, but then I have to copy the contents, delete the border, and re-paste, and that’s stupid. I can also no longer copy part of the text within a cell; if I copy only a word, when I paste, it’s as though I copied everything.

I’ve tried restarting my computer, shutting down my computer, checking for Windows and Microsoft updates, logging in and out of MS365, and extensively Googling the issue. I’ve checked all my paste setting in Outlook and they’re set to default to “keep source formatting”. I’m on Windows 11 and the latest versions of Excel and Outlook, and due to work I can’t revert to an earlier version. I’m going insane; please help me.