reconnection problem fenix 5 Plus

I use an iPhone as a phone and the watch is a Phoenix 5 plus
every time the connection between the phone and the watch is lost for various reasons: the phone shuts down, the watch closes, I go out of range, etc. it does not reconnect automatically, every time I have to search in the phone for Bluetooth devices the watch and connect it. Initially, I suspected that it is from the phone, but I found that it is not, because the phone automatically connects to other devices (portable speaker, at startup it connects automatically, when I get in my car  it connects automatically)
I tried all the options:

  • restart the phone,
  • restart the watch
  • I deleted the connection and I redid,
  • I reset the phone and the watch to the factory settings

Does anyone else have this problem, if so, I'm sorry :(
the question is whether someone has a solution in this regard
thank you