Something is enabling low data mode on wifi on my iPhone(s) from time to time. I usually only notice when I see apps not updating or when I install or want to update an app. It then asks "Are you sure because of xx MB?".
I use (automated) shortcuts in my daily life, but low data mode isn't even an option via shortcuts, only low power mode, which does not trigger low data mode switch inside the wifi profile. My shortcuts do control airplane mode and wifi switch, but I am at loss how any combo's of that could result in low data mode.
Qv1: Does anyone have any idea what could enable wifi low data mode (besides the manual switch inside a wifi profile)?
Additional remarks:
- low data mode is also a switch somewhere under mobile data, this question is not about that switch; only the wifi variant.)
- low power mode is not active when I encounter this state so the battery icon is green.
Additional remarks added after comments and time:
- Wifi profiles are synced accross devices, iPhones and Macs. (Thanks jksoegaard.)
- I disabled the checkbox 'Connect automatically…' for most Wifi networks inside the Mac settings because I do not want the Mac connecting to Wifi networks automatically. (It is connected via Cable.)
- Due to unclear circumstances I had to uncheck all the checkboxes again, it seemed to have forgotten my preferences.
- Later on, I encountered my phone in low data mode again.
The evolved question:
If there is a true causality, I don't know for sure; might be a coincidence. I can only guess on what caused the Mac (wifi) setting's amnesia, so I cannot reproduce it.
Qv2: Could you somehow unintentionally cause low data mode (inside wifi profiles) on your iPhone by changing settings on your Mac related to the same wifi profile?
(Low data mode does not exist on MacOS wifi profile as far as I know.)
Best Answer
As far as I know, there's nothing in standard iOS that automatically changes this setting.
However, there's a few pit falls you might have run into instead:
The setting is synchronised across your devices using iCloud. This means that if you enable Low Data Mode for a specific WiFi network on your iPad, this setting is then automatically enabled on your iPhone. Perhaps a family member is changing this setting on another iOS device which triggers a change on your iPhone - lots of confusion.
The setting is automatically enabled when connecting to Personal Hotspots. This means that if the WiFi network you're connecting to is not for example a home router or an office network, but instead an iPad or iPhone that is sharing its internet connection, then Low Data Mode will automatically be enabled every time you connect.
You might have multiple SSIDs (network names) for your home network, and you're only changing the setting on one them - creating confusion. For example if you have separate SSIDs for 2.4 Ghz and 5 GHz, or separate SSIDs for a guest network or even separate access points in your home, you should be aware that changing the Low Data Mode setting only changes it for that specific SSID. If you later connect to a different SSID on the same network, you'll need to make the change again.
UPDATE: You have since updated your question to basically ask a different question:
There's no setting in the macOS GUI for Low Data Mode. There's no way to set this from System Preferences or any other built-in GUI tool or command line tool.
This means that it is extremely unlikely that you could turn on Low Data Mode for a WiFi network simply by changing a settings for the WiFi network on the Mac.
However, it does not mean that it is fully impossible. If it did indeed happen, it would indicate a bug in Apple's software where somehow changing an unrelated setting makes macOS synchronize a Low Data Mode setting for the network, which your other devices would then pick up.