"Raiding with two accounts on the same internet connection (via mobile hotspot) not possible with v 0.73.1?"

#PokemonGO: I usually play together with my son. As he has no SIM in his phone he uses my connection via mobile wifi hotspot. This is working fine for normal gameplay and did also work for the raids we did until now.The last two raids we did together he got an error after using his raidpass and selecting team, when the fight should have started. It was something like "Joining Raid not possible" (in german words). Unfortunately he hasn't a screenshot.Does anyone else have the same problem?Edit: Thanks for the 1 downvote for asking a question. If i would have known that the hotspot isn't the problem i wouldn't have asked.Edit2: Most likely the error isn't caused by using hotspot, but by time-settings of my sons phone. I will check and give an update. Thanks for all the answers!Edit 3: I just checked his settings, time was set to automatically receive from network and time is shown correctly. via /r/TheSilphRoad http://ift.tt/2x4raP9