Ran into my first supply chain issue today. My burglar alarm uses 3G cellular to call in to the alarm monitoring service. All the cellular companies are supposedly taking 3G away come January 1st. Now the modules they need to switch to 4G are in short supply. They were supposed to come out today to do the upgrade, but called this morning to cancel since they don't have the part. Funny thing is I wanted this system wired into my landline when they put it in, no cellular, but the installer made a big deal about how dated landline connections are and how using the cellular connection would last the life of the system. Wrong. Not too concerned however, because if they can't get the part by January 1st, they can come out and wire the system into my landline. THAT is still supported.