My personal Microsoft Account is causing conflict with my Business account

Question

My Laptop has Windows 11 and it is linked to a Microsoft licence, I purchased a work mailbox to match my Domain from GoDaddy years ago, and this was added as a work account under the Microsoft Account linked to Windows 11. This was just a cloud based version on Office (365 Essentials). But we wanted something where we could actually do an full install of Office, rather than just cloud based. My wife does a lot of my admin, and just doesn't get on with purely cloud based version of Office - particularly Word/Excel. End up with multiple copies of all documents and spreadsheets as a result - I have tried to teach her but following an accident, she has cognitive issues with absorbing new skills. I wanted to make her life easier, so a few days ago I renewed our mailbox from GoDaddy and upgraded it to include Microsoft Business Professional - which is supposed to come with a hard install that can be used offline (the Office version my Wife's brain reverts to when working,, as she learned it about 20 years ago).
Well, it hasn't made life easier AT ALL. We have been getting major conflict between the 2 Microsoft accounts (the one linked to Windows 11 - Google email and the work one linked to #Microsoft Business Professional via GoDaddy).
I kept getting looped when signing into Office Professional. It was saying that my email address isn't a Microsoft Account and circled back to the gmail account linked to Microsoft 365 Essentials (personal account). When I was eventually signed in, stuff sometimes saved to the wrong account, including OneDrive etc. The Gmail Microsoft account being the dominant account, but we need the dominant account to be Microsoft Professional.
I have lost 3 days work trying to sort this out - on the phone for a total of 19 hours with GoDaddy, but going around in circles. I put a support ticket in with Microsoft and was meant to receive a call - still waiting.
I have unlinked, disconnected and deleted both accounts from the laptop. Uninstalled and reinstalled Office, and the same thing keeps happening! The only difference on this last occasion was that my personal OneDrive was empty on reinstalling! It had years wort of stuff - thank God I downloaded to a portable hard-drive!
I am not technically minded at all, so I have been trying my best to understand the stuff I have looked up to rectify the issue - but getting nowhere. I was going to unlink Windows 11 from Microsoft Account next, but not sure if that would cause issues at all? We were going to be cancelling our Office 365 essentials as Business Professional is better for us, and I don't want to be paying for 2 subscriptions when this shouldn't be an issue. But until this is rectified, i am stuck paying both - wishing I had never upgraded in the first place. Sorry for the long one, been incredibly frustrating 3 days being on phone to GoDaddy til 1/2am each day - and still not sorted. Poor Wife is scared to even try and do the admin haha, Any advice would be greatly appreciated. Thank you all :)