After connecting accounts, there are frequent logouts from the game.

Hey there! Sorry to hear about this.

Could it be that you are trying to be logged in on multiple platforms at the same time? For example, if you have Warframe open on your PC, you cannot also be logged in to Warframe on iOS. The same goes for Xbox, PlayStation, Switch. 

If that is NOT relevant to you, could you send over log files so we can understand what might be happening? First open the options menu, tap the Envelope icon, then choose "SEND ERROR LOGS" -- please send me a direct message on the Forums once you have saved zip files. Thank you! 

Also, could you confirm that you meant the logout is happening every minute only on iOS or is this now happening on PC as well?