Bug: Stutter after closing vendor window

[possum-enjoyer]

Addon Version

v0.3.17

World of Warcraft Version

Retail

Describe the bug

Upon going away from the vendor and having the window closed there is a small lag and fps drop. This doesn't happen with betterbags disabled and also happens when betterbags is the only addon enabled

Steps to reproduce

1. Go to a vendor
2. open their trade window
3. go away so that the bag window and the vendor window closes on itself

[shaundrong]

Mostly noticed this in retail 11.0.5 entering and exiting the vendor inventory screen.
There also seems to be some sort of interaction with Profession Shopping list as having both enable increased the stutter for me. Perhaps calling the same function? I don't know of any integration between the two.
Seeing a 30% frame drop with just bb v0.3.18 vs 50% with bb and PSL v11.0.5-004. Don't see any frame drop with just PSL loaded