Chat with Copilot popup on every Excel launch

An ad for Copilot shows up every single time I open Excel. Clicking Not Now closes it, only for it to reopen again when I open Excel later. Is there any way to disable this or remember my selection each time? It is frustrating to have to deal with it all day long.

I do not have a Copilot tab in File > Options. Optional connected experiences is already disabled.

Microsoft® Excel® for Microsoft 365 MSO (Version 2511 Build 16.0.19426.20218) 64-bit

Windows 11 Pro 25H2