Download this beta firmware and upgrade. Go to basic->internet select best suitable band. https://static.tp-link.com/2020/202007/20200714/LTE_GATEWAYv3_1.11.0_0.9.1_up_boot(200325)_2020-06-12_15.48.55

Hi, M facing issue in automatic band selection in my MR6400. Band 3, 40 gives more speed as compared to band 8. But Band 8 gets selected automatically. Is there any beta firmware for MR6400 v4 where w