Problem with alarms on the tandem pump

Hello, I am a new Tandem user and have coped with most of the challenges it presents fairly well. However, I wonder if anyone can give me advice on the following problem.
Yesterday, in a very quiet room full of people my alarm went off as loud as a fire alarm! I rushed out of the room to see that a) I had very High BG ( 19)
and b) there was an occlusion problem ( which presumably had caused the high BG)
However, all my warning sounds are switched to Vibrate so I dont understand why there was a loud sound. It does say in the booklet that the warning for occlusion would be vibrate and then the user must OK this and ( of course) change the sets asap.
I could have missed the vibrations because I was concentrating on the meeting. The booklet does not say what happens if you dont click OK. Is this why the alarm sounded?
I think the occlusion might have happened because I was using some Apidra instead of the new prescription of Novorapid ( though the Tandem trainer said they were interchangeable.) I found some info on the internet that Apidra can cause occlusion and that Tandem recommends Novorapid So I shall not ise that again.
My serious concern though is about being in a concert, theatre, singing in a choir in a performance and having to deal with the alarm again.
So can anyone suggest a foolproof way of preventing this alarm? I can and do check my BG regularly on my phone so I woild be picking up the problem myself pretty quickly. I really dont want an embarrassing earsplitting alarm to deal with as well In a very pi lic and embarassing situation.
I would be so grateful for any ideas or to hear about similar experiences.
Otherwise I experience the pluses and minuses of this CGM pump. I used to be on Medtronic but my nurse was keen to move me to Tandem and CGM. It has a number of irritating features, including waking me up with a vbrate when it has lost connection with the transmitter ( even when it is nearby) I have ruined a couple of sensors because you have to follow a certain procedure in order not to confuse the new sensor. And you cannot restart a sensor once you have stopped it. All hard lessons to learn.
Am I pleased with the switch? Jury is still out.

thank you for this help. I think then that I would consider disconnecting before a situation where I know I definitely could not deal with a loud alarm going off eg in a performance or theatre etc and use my previous ( Medtronic) pump.
I had regular occlusions with that but if you are checking BG regularly then that need not become an emergency and the joy of Dexcom on your phone means that is so easy.
If I do make a mistake in a change of the sensor then I will also try your suggestion. The problem is the lack of interaction between Dexcom and Tandem and the instructions need to be clearer .
I have written out my own set of instructions until they are embedded in my brain!
I also saw later on an American site that Apidra is not recommended and I was using that when the occlusion happened. I have been prescribed Novorapid but because the wastage is considerable 3 vials per month are insufficient so I used Apidra . Maybe others have info on this?
A month into using Tandem and I think I have exerienced quite a lot of its challenges. The jury is still out for me.
Thanks again for your trouble in replying,

With my Medtronic pump I used less than 3 vials of Apidra per month as the sets were changed every three days. With the Novorapid and the Tandem pump there is a built in wastage of 20u in the catridge and the sets must be changed every two days so with 4 fills per vial three vials will only last 24 days at the very most.

Thanks for this. I too have disconnected alarms where I can, because I found the constant vibrations after meals for high BG so unnecessary because when you check there is enough IOB anyway
. I had a call from customer support at Tandem about the loud alarm , who explained that the reason for the ‘fire alarm’ was because I did not click OK to the message As I missed the vibrations. Nothing to be done about this alarm - cant be switched off so I definitely need to avoid this embarassment during certain activities. I had plenty of occlusions over the last 16 years on the Medtronic pump. It was always pretty obvious if I was confident that I had bolused correctly, and then I could deal with it so I don‘t see why you can’t turn this alarm off. I have turned off the HIgh BG alarm because I check my Dexcom frequently on the phone anyway. I have set the High BG alert quite high on my phone too. I realise that we need to be guided by our diabetic team on this issue.
There are other annoying features but the embarrassing fire alarm is the worst as far as I am concerned. I think my choice would be to use Medtronic during the day and Tandem overnight because I have found it excellent in avoiding the ‘lows’ I experienced during the wee small hours.
thanks for the tip about not needing to change the cartridge so frequently. I have decided that changing it every two and a half days suits me and is a good compromise though I am not sure if my team would approve of that.
No going back now on my choice I guess, at least for the next four years.
So pleased to hear that you are doing so well now,; very encouraging. I am glad I signed up to this forum to exchange experiences as I would not underestimate the challenges in switching to Tandem T slim.