i got similiar problem, yet i am the one who fix it.
there's a way to fix it:
1. remove all relays in your client, make it to only connect to an bouncer like bostr. you could use mine: wss://bostr.lecturify.net (allows both read and write)
2. save it and you will see bandwidth usage went reduced 5x than before.
unless your timeline is full of heavy images, it's recommended to disable auto load in your client.
for my case (android), here's my recommendation:
1. very lightweight: nozzle + bostr
2. fair: any client + bostr
