So I was messing around with axolotls, and I discovered that guardians could sometimes freeze you in place with their beams. It seems to only work in groups but I haven't gone into detailed research. All I know is that 1.16 did not have this "feature". Also please see attached video for demonstration. 

https://drive.google.com/file/d/11euSB_huE1Z5dh5NcBLZ5QnwvPP-ymk7/view?usp=sharing