Q: iPhone deleting contacts one-by-one and sending messages to the wrong people

I've got two problems with my contacts that are becoming very cumbersome and have no solutions I could find online.

Problem 1: A few contacts a week are disappearing from all my devices, which are synced up through iCloud. As a result, my messages thread is largely numbers and I have to discern who everyone is. Starting a new conversation is even more difficult. iCloud is the only place I'm storing contacts, and reverting back to a backup doesn't help because it will just delete more contacts next week, besides losing the ones I've added since the backup. It usually deletes the contact while I am texting with them, so I have actually seen the name change into a number several times.

Problem 2: Sometimes I text one person and it will send the message to another person. It's very strange. I can even tell it to text to a number rather than a name, and it will text the other person's number. This usually happens between a husband and wife couple or two people who work in the same place.

I use Messages to communicate for work a lot, and this is very much getting in the way. It's enough of a hassle to make me leave the whole Apple ecosystem, which I'm deeply embedded in, because it prevents me to communicating with people and getting anything done. Yet I can't find any solutions online and haven't even read anything where Apple acknowledges the problem.

Please help, and please tell me the next rounds of OS updates will fix this.