Resolved Conquered City kept my enemy's colors on its banner

[vth_Musketeer]

Summary: I am playing as a vassal of the Southern Empire. I just conqured the City of Akkalat which was held by Khuzaits. After I took over the city, the banner over the city remained the color of the Khuzait Kingdom. I still own the city, but the banner did not switch to the Southern Empire Colors.
How to Reproduce: Open Saved game
Quest/Settlement Name (if related): Akkalat
Media (Screenshots & Video): save file is at the upload site
Version: e1.5.8
Installed community-made modifications: None
Computer Specs:
OS: Windows 10 Home
GPU: NVIDIA GeForce GTX 1660 Ti
CPU: Intel (R) Core(TM) i7-9750H CPU @ 2.60 GHz 2.59 GHz
RAM: 16 MB (15.9 usable)
Motherboard: ASUSTeK Computer INC. G731GU Version 1.0
Storage Device (HDD/SSD): SSD

 

[vth_Musketeer]

Update. Exiting the game and going back in fixed the banner.