Ideas
I've been having this issue for a while. I play on PS4 so no mods or cc. I've noticed it's worsethe longer I play and possibly related to the lagging issue mentioned in other reports where severe lag happens after 30 minutes to an hour of real time. One thing that will occasionally work when my Sim is idle, despite having interactions queued, is to open the options menu and in the background the current Sim interaction that is stuck will clear or move to the active interactions. Then when I close the menu without doing anything else, my Sim resumes what they were doing. There's also a huge delay after switching from build/buy to live mode where the clock will run but my Sim remains idle and I can't click on anything. The pie menu doesn't appear for up to 30 seconds despite numerous clicks and then suddenly they will open and disappear in quick succession until the last object or Sim I clicked on will remain and I can select an option. During this freeze, the cursor stays as the standard arrow but still moves normally. When pointing at something that is clickable the cursor doesn't change and objects don't highlight as usual to indicate there's an interaction available.