WHO has EVER promised you a charge rate of 350 ?? In Europe we get 240 which is plenty and allows for a coffee and nature break.
I don’t think the OP was expecting 350kW of charging speed. It has been published that the Taycan’s fastest DC charge speed should be 270kW. But... the OP lives in the USA where we are given 3 years of free charging at ElectrifyAmerica stations. Those stations have (typically) 3x different towers.
Every tower has 2 cables (though only one can be used at at time). Tower option #1 would be a CCS Combo + CHAdeMO tower (one cable is CCS, one is CHAdeMO). Those towers are all 150kW advertised max power (though I believe CHAdeMO may only allow 50kW? Don’t quote me there)
Tower option #2 is CCS Combo (2x) and has a 150kW sticker/label on the tower. And finally Tower option #3 is the same as #2 but has A 350kW max speed label. Most Taycan users are smart to at least TRY the 350kW towers first, since they might be able to get 270kW there.
(Note: some users have reported using the 150kW towers and getting 170kW — so that is good news)
So again— the OP wasn’t using the 350kW tower expecting it to give him 350kW (at least i hope not; as 270kW is the max the Taycan will see)— but the issue is this: at almost ALL of the EA stations, the 350kW towers are always the most likely to NOT work. Many times they wont even get past the “handshake” part of the equation. Strangely this occurs with many users reporting it. But the 150kW towers work, providing at times as much as 170kW to Taycan owners.
Hope this clarifies—