Strange sudden bank account reconciliation issues, starting balance changed
I am working with company who started a new bank account in 2020. Their operations are messy to say the least but I'm only hired to clean up after they do the daily operations. I had the bank account in question reconciled through the YE 2020, but the staff at company had added their own expense entries hitting that bank account, billing customers from the expense entries. So I went through and using the register changed the R from my entries to theirs one by one. I have done this many times with this company so that's nothing new and I know exactly how to do it.
The problem is that all of a sudden my "starting balance" was off according to QBO. I checked the historical reconciliation reports and the changes made section in particular. The changes all offset each other as I intended. I still got the error. In the past I've seen this but when you just hit Reconcile anyway those R entries equal out and you can reconcile with the correct starting balance, but this time the starting balance was still incorrect. So I saved for later, then resumed. This in the past has solved many calculation issues with Reconcile feature. But not this time.
So I saw the entries causing problems started in September and since I had spreadsheets with data to support bank reconciliation I just un-reconciled through September and figured I'd just redo it and solve the QBO problem with starting balance. When I did this is made it worse! Now the problems went back to just about the whole history of the bank account, or March 2020. So I just unreconciled the entire history of the account, figured that would solve it.
Now its saying that my starting balance is off by $100,000 which is inconceivable and I'm not sure how to fix it. I logged out in frustration and turned off my computer, hoping a reboot and time away would change something if the was some issue on QBO end which it appears.
I'm not sure how to proceed at this point. Advice? The support online chat seems to be out of commission, we're having really bad weather across the USA and perhaps that is another problem. I'll attach some screen shots.

