In Bedrock Windows edition, if a third party texture-pack (from Marketplace) comes with different resolutions and you change the resolution after a game has been played (Setting -> Global Resources -> select texture pack and click on the "wrench icon"), the change (256px -> 128px, 128px -> 64px, 128px -> 32px, 32px -> 128px, etc) does not have any effect: the message "Loading resource packs" appears but the resolution of the resource-pack remains the previous one and you need to restart the game to see the effect.

Steps to reproduce the issue:

1) Open Minecraft and load/create a world
2) Exit the world (Save & Quit)
3) Change the resolution of the texture-pack
4) The message "Loading resource packs" appears but the resolution of the resource-pack remains the previous one.
5) Exit completely from Minecraft and re-enter: the resolution changes.

Note: The resolution changes right away if, instead, you don't open any world before changing the resolution.