Extremely strange OFX direct connect result

[Jack]

I have two Vanguard accounts I have been tracking for several years  
with OFX direct connect.  I recently noticed that neither of them has  
actually downloaded any transactions since the end of last year,  
although the download completes with no errors.  For one account, the  
downloaded OFX result does include the latest price of the held  
security but no transactions.  I have not yet contacted Vanguard to ask  
if they have changed anything.

However, just in case some connection detail changed, I unmapped one of  
the accounts, and tried to re-map it.  Once I entered the login  
credentials (same with or without using the Client Uuid) it showed me  
two possible accounts to map - but both of those are FIDELITY accounts,  
not Vanguard.  One of them is not mapped at all, and the other is  
mapped in a different KMY data file.

I have no idea if this is a problem with the OFX mapping data,  
something going on at Vanguard, or KMM doing something strange.  Other  
than running Wireshark to see what is actually happening during the  
mapping process, does anyone have any clue how a request to Vanguard  
could end up returning info about accounts at Fidelity?

Jack