[Xiaomi Mi Mix 3 Questions & Answers] USCanthony:
Notifications are awful. I have yet to have a notification display on the lock screen. When I do receive new mail or an SMS message, it can take up to 40 minutes before notifying me if the screen is off. If the screen is on I get the notification within a couple of minutes but that is only if the screen is on. Screen on means the screen is being displayed and the lock screen has been dismissed. It does not mean that the always on ambient display is on. That is just as bad as the display being completely off which makes me think that the problem lies with the phone being locked and is not just an over aggressive doze problem. I am using the notification repeater app and I also use Auto-notifications with its notification categories feature. Both of those have helped a little bit but it is rare that I get a notification within 10 minutes of my phone receiving e-mail or text messages when the screen is off (10 minutes is actually good).

There is also an issue with Android calendars. These aren't the calendars attached to your gmail account and they are not local calendars as well. Android calendars are usually created by 3rd party apps that offer holiday calendars for every country, sports scedules for every NBA, NFL, MLB, NHL and NCAA teams (motor sports and European football in some apps). The apps that also create TV listing calendars create their calendars as Android calendars. Any calendar app for Android can display them and you can choose to display or hide them individually within any android based calendar apps. Not with MIUI though. I can see them in the settings of any calendar app I install and can set them as hidden or viewable but they will not display as a calendar in any calendar app. MIUI has a few nice features but it is not worth the lack of timely notifications and it would also be nice if I could actually display all of my calendars. I have gone the custom GSI route and there were issues with every GSI based ROM I tried. I could install every GSI ROM I tried. I could even install Resurrection Remix GSI without a problem (repairing and resizing the system partition so you can install GAPPS is easier than most people realize. I kept running into deal breaker isssues with each GSI ROM though. I don't remember what the issue was with BlissROM but I do remember taking half a day to try and find a work around to no avail. Pixel Dust had an annoying random reboot problem and Resurrection Remix seemed to work just fine until it randomly would display a Setting up phone message after logging into the phone at a very random time. It would sometimes do this somewhere with the first few hours of use but could go as long as a day and a half before doing it. The only way to get past that screen was to get into the phones settings and clear out your fingerprints and set the phone to not require any type of password, pin or pattern. Once you clear those out the phone will continue to boot. If you want security you will need to setup security again and you will find yourself doing this all over again anywhere within the next hour too 24 hours. This is a known issue and there is a thread about it. It is a ROM issue because it is doing it on many different brands of phones. It is doing it very randomly though and the developers of the ROM have not had it happen to one of their phones yet. It makes the ROM unusable for those of us that are running into it though which is why I am back to MIUI (eu version) and in my opinion, MIUI ruins what would be a very good phone experience.