Power Spikes Disconnection

Hi all , i need some help about a power spikes problem.

My trainer is a TACX Flux , connected to ZWIFT by a MAC PC ( bluetooth ) but the same problem happens in different platforms with different connection type too ( PC Windows / Android Tablet bluetooth/ant+ ).

The problem is simple to explain : during a workout needing high power spikes by get out of the saddle ( more than 550W ) ZWIFT APP and TACX lost their connection , in a result of 0 Watt power output for a while , then all go back ok.

I guess a TACX problem , but with TACX APP that doesn’t happen.

Further , without power spikes all is good , meaning that if i want to reach an high power in a gradual way ( pedaling sitting on the saddle ) there’s no problem.

Has anybody faced on this issue ?