I put 9 mining drones to mine 9 tiles of uranium, and at first it was OK like the img on this link
https://imgur.com/a/S0HQBhH

but after some time, before the uranium ore get empty and before the mine depot has a lot of ore, the drones stop gethering like this img
https://imgur.com/a/f00Wm8Q

and the only way to get back to normal is removing the mine depot and place it again

Is the mining depot full?
Does it have enough acid?

Is the mining depot full?

No, note that i have a blue isnerter pulling out the ore and its empty

Does it have enough acid?

yes, if i just remove the depot and place again, it works normaly

i made some tests, with more uranium processing machines they stay around 4/5 miners
https://imgur.com/a/DRZIh3Z
but i cant say why with only 4 machines this still happen

can you provide a save game of them not mining?

sorry for digging up,nut it seems i have the same now ,screenshot : https://imgur.com/a/Oj53arY
as you can see,the mining outpost got 100 miners out,but they are all stacked outside,not coming in,they just stand there
the depot is not filled up at all
save game :

https://drive.google.com/file/d/1Y3UjzM4dRvxosDy7gJwj4Ig2Z8hDykCc/view?usp=sharing