Cannot detect mobile hotspot

Question

I am using lubuntu (Ubuntu 18.04.06 LTS) linux 4.15 on my ancient 32 bit dual core T540 @ 1.66GHz. But recently I have been facing internet issues with network manager where the machine is unable to detect my mobile hotspot for at most 90% of times but it easily detects and connects my home wifi. I am using 2.4GHz of band with both mobile and home wifi. There is a rare chance to find the network if I keep restarting network manager. Network Manager version is 1.10. I have tried many solutions from forums but none of those have worked till now. I do have power management turned off.

iwlist freq

lo        no frequency information.
enp6s0    no frequency information.
wlp4s0    24 channels in total; available frequencies :
          Channel 01 : 2.412 GHz
          Channel 02 : 2.417 GHz
          Channel 03 : 2.422 GHz
          Channel 04 : 2.427 GHz
          Channel 05 : 2.432 GHz
          Channel 06 : 2.437 GHz
          Channel 07 : 2.442 GHz
          Channel 08 : 2.447 GHz
          Channel 09 : 2.452 GHz
          Channel 10 : 2.457 GHz
          Channel 11 : 2.462 GHz
          Channel 36 : 5.18 GHz
          Channel 40 : 5.2 GHz
          Channel 44 : 5.22 GHz
          Channel 48 : 5.24 GHz
          Channel 52 : 5.26 GHz
          Channel 56 : 5.28 GHz
          Channel 60 : 5.3 GHz
          Channel 64 : 5.32 GHz
          Channel 149 : 5.745 GHz
          Channel 153 : 5.765 GHz
          Channel 157 : 5.785 GHz
          Channel 161 : 5.805 GHz
          Channel 165 : 5.825 GHz
          Current Frequency=2.417 GHz (Channel 2)