If you are open to use different types of gates, here is what you can do (all values are default, for illustration only)

^{simulate this circuit – Schematic created using CircuitLab}

The RC delay will keep NOR gate output at 1 from the beginning, then switch to NOT function as required for oscillation.

Having said that, there is still "twilight" zone on the power up where gate output might be undefined. Adding pull-up on the output might help with that, but it will affect the oscillation frequency somewhat.

If you are open to use different types of gates, here is what you can do

^{simulate this circuit – Schematic created using CircuitLab}

The RC delay will keep NOR gate output at 1 from the beginning, then switch to NOT function as required for oscillation.

Having said that, there is still "twilight" zone on the power up where gate output might be undefined. Adding pull-up on the output might help with that, but it will affect the oscillation frequency somewhat.