Philipp Indeed, Targobank is an RT1 participant and should be able to send instant transfers to DE IBANs. If they are sure that the money was send as SEPA Instant and there haven't been any errors, the money should be in your bunq account now.
That would mean that it is likely that either the processing at bunq wasn't successful or bunq halted the payment because their fraud detection system marked is as high-risk and they need more information from you. In both cases it's best to contact support as you already did and converse with them.
The other option of Targobank sending it as a regular transfer also exists, but then Targobank should also be aware of that, so if they say that this is not the case, you would be able to rule it out.
