Grove GPS (Air530) RX-pin not working?

I’m unable to send commands to the Grove GPS (Air530) module. Checking the schema (and also by measuring the pin) the Air530 RX pin is pulled high to 3.3V on the PCB while the datasheet says it’s only 2.8V tolerant, is this by design or am I missing something?
Even if i remove the pull-up resistor and try to use the RX pin on the chip directly (using 2.8V TTL) it won’t respond to the commands but only keeps sending the standard NMEA messages.
I bought a second module in the case that the first was defective but both behave in the same way.

Any help appreciated.