Help LG E975 4G network slow speeds

[Froyooo]

So, after 2 weeks this has happened to me. Always in 4G network i will get 1-3mb/s download and 1-2mb/s upload .. The H connection works well. There is like 2-3 bars on 4G and still, not working good.

How to fix this? Should i do factory reset or something?

Phone: LG E975


Thanks!