My iPhone suddenly won't work as a personal hotspot for my iMac

[DebbieL]

I have been using my iPhone as a personal hotspot to allow me to connect my iMac to the internet in the absence of any other connection (we moved house just as the lockdown began and we have no landline or fibre connection). I have a pay monthly contract and had to buy a 16GB data bolt-on to enable this - expensive, but needs must (I am supposed to be working from home). However, with more than 4GB still left of this bolt-on (according to the account info on MyO2), the iMac suddenly cannot connect to my iPhone. It can connect to my husband's iPhone, and my iPad can connect to my iPhone, so it doesn't seem to be a hardware or software issue. Having looked at the amount of data various devices in the household have used from my personal hotspot, my iMac has used the most, and it has used exactly 4GB before I stopped being able to use it. This makes me think there must be a hidden cap on the amount of data any one device can use, but I can't find any information about this on the O2 website, Aura was no help and I couldn't get through to an actual person on the phone. Does anyone in the community have any knowledge of this, please? 

[MI5]

@DebbieL 

Check the settings on your Mac and change it from a metered connection.

[DebbieL]

@MI5 Thanks for this - please can you tell me which settings to check? I don't know where it is set to be a metered connection!

[MI5]

@DebbieL 

It will be in network connections.

[DebbieL]

@MI5 I'm afraid it isn't! I'm using macOS Mojave v. 10.14.6. I can't see any settings relevant to the connection to my iPhone other than the personal hotspot password.

[gmarkj]

Is there not an option to define the type or properties
of the connection?

[DebbieL]

@gmarkj Literally only "Automatically join this network" (or not) and where you want to put it in the order of priority of networks for connection. 

[gmarkj]

Oh. Not a Mac user so wasn't sure (this option exists on Windows).
Have had a google, and apparently Trip Mode does the same thing.
Have you triggered that?
Some links:
https://www.sindastra.de/p/290/how-to-save-data-while-tethering-or-on-public-wifi-with-windows-10-ma...

[DebbieL]

@gmarkj Thanks for the link. As the article says, it's all done for you on Apple devices, so there seem to be very few opportunities to inadvertently cap the amount of data you can use.  I haven't got Trip Mode, so I don't think that can be causing the problem. I haven't got the phone in low data mode, either. I am basically trying to let the iMac have all the data it wants from my mobile phone account, and it's not taking it or even seeing the iPhone connection. I am very suspicious about the fact that it has used up exactly 4.0 GB before being cut off - as if someone somewhere has decreed that that is quite enough for one device to have eaten up and it must now stop and let some of the others have some!

[jonsie]

I'm guessing O2 have deemed it as a breach of their fair usage policy.

Strangely enough, on the old unlimited Simplicity tariffs, customers were told that suddenly, unlimited data meant 4GB.

Nowhere was this ever written down but customers were sent a text after reaching 4GB. Anyway, their fair usage is very much determined by theirselves and here is their ake on the fup.

https://www.o2.co.uk/termsandconditions/mobile/o2-consumer-fair-usage-policy