Just made a custom monster with the "rollable" tags. It is displaying correctly when I view it in my homebrew collection by shows the code when viewed in the encounter builder. 

Thoughts on what is wrong?

Monster: https://www.dndbeyond.com/monsters/2647114-gonzalo

Encounter: https://www.dndbeyond.com/encounters/b3a43a1f-a853-45cd-84a5-8286ab1faa53

Thanks!

You have some invisible characters in there. Probably some “ ” where there are supposed to be spaces, probably artifacts from a copy/paste gone wrong. Up at the top of the description field look for the button with the following symbol:

</>

That will let you see the raw html code. From there you can get rid of any errant code.

Thanks. I check this and rewrote it. Got the "to hit" to work, but the damage calc is just showing me the part in red below, but doens't have the rollable button in the encounter.

(1d8+1);{"diceNotation":"1d8+1,"rollType":"damage","rollAction":"Longbow","rollDamageType":"piercing"}

I have the rollable tags in there and / to close it, fyi

I've been over this several times is there a coding error I'm missing?

You’re missing a quote. Try this:

{"diceNotation":"1d8+1","rollType":"damage","rollAction":"Longbow","rollDamageType":"piercing"}

Facepalm! That is it! Thanks!