I have tried ringing about this and lodged a fault report already and have not heard back.
I have both an Optus 4G mobile service (100GB) and a mobile home broadband service (500GB). I have been living in my current house for 8 months and have been using both of these services without issue for that time. We usually have full signal and speeds usually very good as we live only 100m from an Optus mobile tower. We use our mobile home broadband for all of our internet services (including streaming 4K video and downloading large files) and usually see speeds between 20mbps in peak to 90mbps during off-peak.
Just over 60 hours ago we noticed that the speeds on both of these services reduced to nearly zero. We still have a 4G connection however it is only weak (my phone shows one bar). It is nearly impossible to stream any kind of video which renders our internet useless since this is it’s primary use and we have all of our other paid services (Foxtel, Netflix, etc.) relying on a fast connection. We can’t even watch free-to-air tv since this relies on an internet connection through the Foxtel box.
I have checked the outage map and there are no reported outages in my area. I need an explanation of how it is possible to be living with a mobile tower basically in our backyard and to be receiving weak 4G signal and internet speeds so slow that it becomes unusable. I also don’t believe this could be caused by heavy traffic as the speed reduction happened very suddenly (down to less than 1mbps!) and has stayed that way for 2 days so far.
Optus aren't great at "getting back". If you lodeg a report you'll probably need to call back to find out any update. Apparently their outage map is also on the blink at the moment as we have got a few random reported outages that never show up on the map.
But you should rule out your equipment. Having two devices is a good start. Any chance you can check and see if a phone from another provider works in your area? Also does your phone work properly when you head out for a drive?
It could be some new interference that is causing the issue) Hope Optus get back to you with a good answer soon.