Train Poznan to Berlin not able to be booked.

Hey everyone! I am currently traveling in Poland with interrail and I was looking at the train I want to take back when I'm done with my trip. I found a train at 07.30 from Poznan Głowny to Berlin Gesundbrunnen and then onto my destination.

However when I want to find this train for the 10th of July it doesn't show up in any app.(Interrail, pkp, DB). It doesn't show up that entire week, while the 2 weeks before it, (so the next 2 weeks) it does show up. I would really like to take this train as it would lead to me only needing 2 transfers instead of 5, 6 or 7 for the other options.

Am I booking too far in advance? Surely not as it's only 2.5 weeks from now. Is it sold out, fully booked? I tried to find answers but I can't find it anywhere.

(Btw I have enough travel days and inbound/outbound days etc. and its within my pass time of 2 months.)

Thank you :)