As others are saying, don't go off of signal bars... They are a visual representation only. Now especially with LTE, the signal bars also take into account signal to noise ratio as well, so you could have a strong signal, with "junk" in the air and it could change the way the bars look.Update
Got my iPhone SE today but it's DOA haveing Signal issue. Too where my Samsung S7 was haveing no issues With my Samsung S7 I was getting full bars in my room. With my Iphone SE am getting nothing but 2 bars any ways not sure if I got a bad one or if T mobile dos not work well with iPhones up here it seems like android works better up here the. iPhones do. Any way am not vary happy right now
Bottom line, if it works well, keep it!