Clickable signs not working

Server version: Paper Spigot latest (java 8 - Current:1.16.4 #484
Error: When using the Plugin BlueShop the signs dont seem to want to activate upon right clicking, this action should open a gui panel.

Error 2: When using the plugin iridescent The hex codes dont seem to want to work.

Reason: Only theory I have is that during an auto patch, it broke the signs functionality and hex code.

Upon trying to downgrade many errors popped up about loading newer chunks and would freeze on restart.

Hey there. This is probably related to a recent Paper update (Adventure). You should be able to use #472. https://papermc.io/downloads while this issue gets investigated.
The second issue, I am not as sure about. I would be curious to hear some more information on what isn’t working properly there.

I would investigate further on the BlueShop plugin, but it seems it is both a premium spigot plugin and little recent activity so uncertain if we can get the information we need to resolve the specific problem. I am going to try and message the author and see if they have some information that can help.