When I add to my character’s hit points on Manual mode using Override it works fine, but when I use a long rest with “Reset Maximum HP changes during this rest” checked it reverts to my old hit points before leveling. This occurs even when I’ve taken long rests without the option checked first.

My understanding is that the checkbox option is to clear max hit point changes that happened during battle, etc. How do I make max hit point changes gained from levels permanent?

in the character builder on the class section you have manage HP. you can update the rolled HP there

Don’t add your Constitution modifier to your Rolled HP, the system will do that for you automatically.

Thanks for the responses, but that's already what I'm doing. What I'm saying is that when I take a Long Rest with “Reset Maximum HP changes during this rest” checked it reverts to my old hit points before leveling. This occurs even when I’ve taken long rests without the option checked first. So, for example:

- I level from 2 to 3 and roll to go from 14 max HP to 20 max HP.

- A couple of game days and long rests go by where I don't check the “Reset Maximum HP changes during this rest”

- I'm hit by a monster that reduces my max HP by 4 points, to 16.

- I take a long rest and check the box to get rid of the monster's effect. My HP max, instead of going back to 20, goes to 14.

I guess another way to ask the question would be, is there a way to update rolled max HP from leveling and a different way to update max HP changes from other sources? I feel like I must be missing something.

You’re adding them to the wrong field. You need too add the tip the “rolled” HP field.

That would make sense! Thanks for your patience.