I had one vendor name out of thousands that I errantly put a space (literally hit the space bar one time) in front of and it threw my entire system off as reported by all the other contributors on this chain.  This has vexed me for months! I finally resorted to individually entering statement and account charges which took loads of time.  BUT...with fresh eyes I looked into it today and worked out "my" problem.  See below on what worked for me.

I went to Vendor Center --> Clicked on the drop-down arrow next to 'New Vendor' --> selected 'Add Multiple Vendors'-->clicked on the 'view all' vendors.

I noticed that a vendor starting with the letter 'R' was listed first (yes, above my number named and letter A beginning names) and its formatting (a literal one blank space before the letter 'R') was off compared to the rest of the list.  I fixed that by back spacing the measly one space and saved my work.  I went directly to bank feeds and viola...it was working beautifully again.  I am not sure if anyone has suggested to look at this issue through the "Add/Edit Multiple Vendors" approach, but it put my problem "Name" at the very tippy top of the list and that is literally all that it was...one space. 

I hope this helps someone else out there!  Good luck!!!