My Android phone goes on to sleep mode automatically every night, it’s great as I don’t have to think about it and I don’t get disturbed by it while I am trying to sleep. Until 4 am when my monthly Netflix subscription goes out and I get woken up by a load ka-ching noise.
Why doesn’t Monzo respect night mode or at least set it’s on night mode? Nobody needs to know that their Netflix got paid at 4am.
Are you sure it’s not your phone settings?
I’ve checked. Everything stays quiet all night, just not Monzo.
I don’t want to turn of their notifications as they’re very handy. I just dont want any at all during the night. My sleep is too precious and rare these days 
Does the sleep mode have an “allow list” (or excluded list, depending on which way round you think about it)? If so, have you checked Monzo is not on it?
Why not switch the phone off when you are sleeping and then switch it back on when you wake up?
Alternatively use airplane mode.
What is night mode? Is that new/different or do you mean do not disturb mode?
Perhaps this is where the issue lies.
What Android phone is it? And what version of 
is it running?
I am not the OP but I would never turn my phone off at night. I don’t have a landline and if my phone was off I wouldn’t be contactable in case of emergency.
My phones DnD mode allows for certain calls to break through.
My DND certainly works, I’ve been still awake at that time scrolling through my phone and not had any kind of external notification when something’s been processed.
As others have suggested check all the options there’s likely to be something amiss on them.
Sorry please ignore me. It seems my phone turned off my Night Mode when it updated. Its a Sony Xperia Android 10. Night Mode is basically DND but with an automatic schedule so you don’t have to remember.
Glad you’ve sorted it 
My phone has this annoying feature that when it’s rebooted the screen is set to auto brightness😡 no way to stop it doing this and annoying as hell when you’re blasted by light after forgetting I need to switch it off
Ah, then a ‘custom skin’ of Android with differently termed features (‘Night Mode’)
It’s not quite the same on my Pixel 5, but I do have schedules set for weekday/weekend nights to automatically switch to DnD mode - and nothing except emergency calls gets through that - not even 
notifications.
Glad you’re running properly now though 
Hopefully or I’ll see you again next month 
At least you can get some quality 
before then!