I totally agree with Betta. Adding loaches to your shrimp tank would be a great idea. They are known to be peaceful with shrimp and won't cause any harm to them. Plus, loaches are really interesting to watch and they can help keep the tank clean by scavenging for leftover food and algae.
Another option you could consider is adding small rasboras or dwarf gouramis. These fish are generally compatible with shrimp and won't pose a threat to them. Just make sure to provide plenty of hiding places for the shrimp so they can feel safe and secure.
However, it's important to keep in mind that every fish is different, and there might be individual variations in behavior. So, it's always a good idea to monitor the tank closely after introducing any new fish to ensure the safety of your shrimp.
Hope this helps! Let me know if you have any other questions.