I have a couple more I saw in this book I am reading. "Shenadoah Summer" by Scott C. Patchan. "The 1864 Valley Campaign."
On page 301, he has the 8th Virginia Cavalry losing their "flag" (Captain Kerr) Union captured the flag. Battle was "Moorefield" Virginia. The 21st Virginia Cavalry were mostly captured, nothing on if they lost flags, but if they did it was at "Moorefield." The 1st and 2nd Maryland Cavalry Battalions (CSA) were hit first around 3am. The pickett's were captured with no shots fired.
The Union 8th Ohio Cav, 3rd West Virginia Cav, 14th Pennsylvania Cav, 1st West Virginia Cav and 1st New York Cav were in the attack.
I'm sure more flags were captured, but not turned in or reported captured.
Have a good day, Charles
Shawn Prouty