Animate won’t let me add keyframes between keyframes. Please help!

[defaultklaajm86xqj1]

Hello! When I try to add a keyframe between another keyframe, it won't add a keyframe. All it does is go to the next keyframe as if I simply selected the next one. It wasn't doing this problem before. My Adobe animate software and MacBook Pro laptop are both up to date. I even uninstalled Adobe animate and reinstalled it and I'm facing the same issue. This is very upsetting. What do I do? Thank you! 

[n. tilcheff]

If you post a screen recording showing the issue, you will have better chance of  someone helping you.

[Nick Gioia · Accepted solution]

Click on the key frame you want to expand, press F5 that should expand your key frame longer than you can make more key frames with F6.

[defaultklaajm86xqj1]

It worked! Thank you so much!