It's all connected. You're heels are coming up because you're tipping forward. I do the same thing. Just keep telling yourself to open your chest and sit up. Once you get your core muscles back in shape, it should fix itself.
Thanks, my core is one thing I need to work on big time, not riding for a couple of weeks, having surgery... Well let's just say it's not the best for it :)
And I do ride with a dressage whip :)
I just need some exercises even ones off the saddle that can help me, lessons are going to come but probably not as soon as I would like, but you never know how I can swing things, have to work on my availability and my instructors.
But I also find when he's out/ at a different place he's generally more forward, so I'm not having to use my leg as much and I'm pretty sure my heels stay down and I don't tip forward as much...
I think I may be overthinking it, but when he's going slower, I think I tip forward to try and encourage his forward, or maybe my heels go up to try and get him to go forward and it's the whole thing again, I don't really know, have to start taking my lessons again