the answer likely depends on what counter trap you're trying to use.."trap jammer" for instance can be triggered only during battle phase. Where as 7tools of the bandit can be triggered in any phase provided you have 1k HP to use it.
At the start of the battle phase, Anti magic arrow don't want to activate and same things for storm
94/5000
I do not understand why I'm not asked to activate my trap cards when he declaims nightmare wheel... it's a bug ? I'm the only one to whom it happens ?