Oracle APEX 5 nested Label not selecting input -

i have upgraded oracle apex 5 , had strange issue of inputs not being selected.

i narrowed down controls nested within label.

it seems if there no 'for' attribute , 'id' on control fails.

//this not check input <label><input type="checkbox"><span>this test</span></label> 

so can manually change prove works.

<label for="chktest"><input id="chktest" type="checkbox"><span>this test</span></label> 

however if save above html file , load , both work.

i noticed in older apps in apex 4 inputs work , wrapped in label element....