Hola! It never occurred to me to click on my home city anyway for a missing Tribute! Thanks @Athrillskr, I’ll have to try that.
So… if this is true it’s a graphical glitch then… which apparently is occurring across both PC and console versions. A graphical glitch might also explain why a force quit and restart could sometimes pop the Tribute icon back into existence, but not all the time.
In this case the (visual bug) issue may also be related to what @Shimrra reported four days ago in Income/Tribute Collection Indicator Gets Jumpy: