98 Impreza problems with hi lo gearbox

[AverageBoss3838]

I've just bought my first Subaru and sometimes when I come to a stop the hi lo gear thing tends to not stay in hi as it locks the wheels so I have to turn the engine off the on put it in low release the clutch then bang it back into hi and then it drives fine the. Has anybody else had this issue? All pointer are greatly appreciated. Thanks