Apple Watch 7 optimized charging not working

I have the same issue?

I have the watch 7 and 15 pro max, and both aren’t stopping at 80% they just charge all the way to a 100.

For a Series 7 Watch, I think you may be misinterpreting what happens with Optimized Battery Charging. Your watch should be fully charged when you take it off its charger. What it does however, is stop it from charging fully until it knows your schedule and when you are most likely to remove it from its charger. Read this carefully and note the part I highlighted:

With watchOS 7 and later, your Apple Watch learns from your daily charging habits to improve the lifespan of your battery. This feature, called Optimized Battery Charging, is designed to reduce the wear on your battery and improve its lifespan by reducing the time your Apple Watch spends fully charged. Optimized Battery Charging is on by default when you set up your Apple Watch or after updating to watchOS 7 or later. 

When the feature is turned on, your watch delays charging past 80% in certain situations. In these situations, the watch's battery level remains between 75% and 80%. Your watch uses on-device machine learning to learn your daily charging routine so that Optimized Battery Charging activates only when your watch predicts it will be connected to a charger for an extended period of time. The algorithm aims to ensure that your Apple Watch is still fully charged when you remove it from the charger.

This would indicate it should be at 100% when you remove it from the charger. I'm going to assume you put your watch on its charger when you retire at night and don't check the battery level in the middle of the night while you sleep?

Now, with Apple Watch Ultra, it is different and it's "Optimized Charge Limit" (as opposed to Optimized Battery Charging) and usually will charge your watch up to 80% as opposed to 100%, likely because the battery is larger and most people don't need their Ultra to be at 100% when it is removed from the charger.

Please take a look at About Optimized Battery Charging on your Apple Watch - Apple Support and consider whether your pattern of usage (or lack of a pattern) might be defeating the necessary learning for optimization to occur.

You're welcome. You don't need to manage charging at all. Your Apple Watch, iPhone, iPad and MacBook if you own one, do the battery charge management for you. Put your device on its charger when you go to bed at night and forget about it. None of your devices can overcharge. And Apple designed them to charge to the levels they need to charge to. In the case of Apple Watch and iPhone, it means you don't need to follow any "rule of thumb" mentality at all. It's not a great idea for your devices to dip below 20% often (and I suspect you rarely, if ever go that low). But you certainly don't need to be mindful of anything else. Put your watch on its charger and forget it.

You're very welcome.