Yep, he wasn't.
2019 Monte Carlo Masters champion Fabio Fognini wasn't happy with Stefanos Tsitsipas' frequent interactions with his father, Apostolos, and he voiced his displeasure following their Monte Carlo clash.
The Tsitsipas coaching thing is a very well known thing in tennis with his father known to talk nonstop during points and rallies. That talk is presumably instruction for his son who is known to change tactics dramatically during matches that shift the momentum in his focus. Many doubt he comes up with that on his own and many have voiced displeasure about it.
The ATP intervened a couple of times but the umpire generally avoid giving penalties to him despite knowing what is going on. Otherwise, the Greek would be defaulted most matches. Tsitsipas has also publicly backed coaching to be legalized in tennis, something many tennis purists frown upon. One of them is Fognini who is publicly against it.
The Italian wasn't happy after their match giving him a cold handshake. Shortly after that, he shared a message on his Instagram Story.
"Coaching or not coaching, that's a big problem!".
Fognini tagged the ATP in the story calling on them to do something.
Yep, he wasn't.