Why not just use a 555 timer?
This should be unnecessary for the TDA7492P, which has mute and standby inputs, that can be used to delay the turn on and avoid any audible clicks, during power on.
In this case, I think this has nothing to do with the speakers. You'll probably find the board still draws a huge inrush current, even with the speakers disconnected. Refer to the circuit on page 5 of the data sheet. It has a 1000µF capacitor (C32, next to J2) across the power rail, which is probably causing the problem.
https://www.st.com/resource/en/datasheet/tda7492p.pdfTry adding a 22R resistor in series with the amplifier board, for the first second, after applying the power, then bypass it with a wire link. It will limit the current to a safe level and stop the BMS shutting down. A more permanent solution is to use a timer relay (either a 555 & relay or you might be able to find a module) to bypass the resistor, after 0.1s to 1s, of the power being applied.
The above solution will only work at low power levels. You need a more powerful BMS which is capable of providing the amplifier, with the current it needs, otherwise this will happen again, when the volume is turned up too high and there's lots of bass in the music. Your amplifier needs a power supply capable of providing 6A peak, to stand any chance of being able to work at full power. Even changing to an 8R speaker will still cause the amplifier to draw more current, with the volume turned up, than your current BMS can provide.