Service

Is there any way to disable LTE on an iPhone software version 15.2? The service where I work is poor, we have boosters in the office, up until I updated to 15.1 I could switch to 4G and could do anything I wanted, since updating I can’t switch and the LTE service is so poor I can only text. Text, not iMessage, my text are green like I own a Samsung or something. Meanwhile, my coworker with a Samsung watches videos all day.