b525s trying to connect to another tower

hi, i hope you are doing well guys

i usually have only this b20 800mhz station available in my area and the router connects to it normally. recently,i have discovered another IMT-I 2600mhz tower by using cell mapper on my phone galaxy s7 edge. i would like to connect to this tower,despite the bad signal. i'm using a pair of yagi antennas on my b525s router,they are optimized for 800-900mhz bands and i have very good gain with them. i haven't managed to connect to this second tower so far,neither on my phone/router. so i came here to ask you guys,how to do it?

i guess it's much easier to walk around and find the best signal from that tower with my phone,so how to set samsung s7 edge strictly to 2600mhz band? and do i need to root it? please take a look at the photo below,thank you in advance!


https://i.imgur.com/oFMhOQt.jpg

Edited by Alex1992 (Mon 08-Feb-21 00:27:26)