tf negative time change messages

edit

I suddenly started getting a lot of messages like these

Saw a negative time change of -0.000165 seconds, clearing the tf buffer.

and am not surprisingly having a lot of trouble with code that relies on tf now. I can't think of anything that changed, and am at a bit of a loss. There's a ros-users message about this from a while ago, but no real solution.

EDIT:

tf_monitor is also showing that all my static_transform_publishers have negative average delays.

Also, all nodes are running on the same machine, so there are no issues with clocks not being synced. This is all with live data, no bags.