Can't joinRamdom Room with Unity 2019.3.2f1

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Hello,

I tried the Pun Basic scene in Unity 2019.3.2f1. I can start it, but if I start a build (in addition to the Unity one), it does not find the room and so create a new one.

However, when I start two builds, it works as expected.

I tried the same thing in Unity 2018.4.6f1, and it works perfectly.

Is this a known issue, is there something that can be done to have it work on Unity?

Thanks