Smartphone Webcam stuttering

Hi,

I want to use the Adobe Connect App on Smartphone to share the Smartphone camera. When using the smartphone in Portrait, it’s not stuttering, but aspect ratio will not be adjusted, it looks like Adobe still keeps the ratio like it was Landscape. When moving the smartphone to Landscape (to get good aspect ratio in Adobe, and I mainly need Landscape view), video starts to stutter quite heavily.

I have tried last week with IPhone 6S (iOS 14.4.1) and Samsung S9+ (Android 10), both I have tested with current version of the App "Adobe Connect" and "Adobe Connect New".

Wifi was good (google speedtest said upload rate is 80 MBit/s).

Ratio in Adobe Settings and in Smartphone camera both is 4:3

Do you have any ideas how I can improve the situation?