Hi Metin, 

I believe some clarification is required here, have you witnessed the application as actually installed on the device or just available when the "mandatory application" you configure gets deployed?   This may be where the confusion around this comes into play.

Applications do not install automatically even when set to mandatory - it will just keep prompting making them mandatory that they accept and install it.  Suggested applications will not prompt and can be installed at the discretion of the user.

With regards to the webclip removing from the device I'd have to get some information about the version of iOS on the device and look for known issues as that is not an expected behavior.

Regards,

Hi, Thank you very much for the information

I am sure of that app was installed before. Yes, it prompts users to let them install. Some users witnessed the removal while they were using the app. 

the version of IOS on devices changes 10.3, 11.4, 12.0. There isn't any consistency in device İOS versions. 

a few days ago, I have added a password requirement to the Add Device rule. Do you think this can be the reason? I enabled password authorization on add device rule after device already enrolled. 

Yes Metin, this could be the reason for the removal, having both configurations on the same profile.

Perhaps it is installing the new (updated) profile based on the additions and is adding it as new on the device, so any previous configurations you had in the same profile are also being "reinstalled". 

Once you have your devices configured try adding new configurations in a separate profile.  If you do not have both in the same profile please let me know the steps you took when enabling the password policy so that I can verify if anything like your use case would warrant this behavior.

Regards,

Are your iPhones configured to be in "supervision" mode?

Are they DEP (Device Enrollment Program)  devices?

Hello,

To clear up and explain in more detail, our iOS apps are B2B apps and they are served over Apple VPP store (Open to only assigned users). The issue happened some of our customers randomly (around 8-10 users) whom found their applications deleted when they checked their devices. We suspect that when there is not enough storage on the server SOTI deletes applications from devices.

I'm sorry you haven't answered my questions:

  Are your iPhones configured to be in "supervision" mode?

  Are they DEP (Device Enrollment Program)  devices?

For VPP,  device-based assignment is preferred.   User-based assignment and redeem code  should be avoided as much as possible.

Also, what are the version and build numbers of your MobiControl server?