Rogue Sneak Attack and 5E OGL sheet

Scouring the forums, I found some posts that suggest that the best way to implement the rogue's sneak attack, so that when the character rolls the damage dice, it automatically rolls the sneak attack dice as well, is to change the damage of the weapon as given in the "Attack" block to, for example: 1d6 + ?{Sneak Attack|No, 0|Yes, [[ ceil((@{base_level}) / 2) ]]d6 [Sneak Attack]} I also change the crit damage to the same code so that when there's a critical hit, the sneak attack dice are rolled again. The problem is that Roll20, for some reason, seems to constantly be changing the damage to: 1d6  + ?{Sneak Attack|No Sometimes it changes it as I'm editing things - that is, when a new weapon is dropped in and I go to change the damage, I'll put in the first formula but when I hit TAB to go to the next field, the damage gets changed to the second form.  Sometimes it changes between sessions - that is, it'll be fine for a session but the next time I log in, it's somehow changed to the second form.  So far it has never changed the code in the "crit" section, only the damage part. I've had to fix the sheet more than 30 times in the last two weeks, for 4 weapons (120 fixes).  I don't know what's going on.  But, it's gotten to the point that this feels unworkable as a way to do the sneak attack damage unless I can figure out what's going wrong and fix it permanently. Can anyone suggest a way to implement the sneak attack to do the right thing that doesn't involve changing the damage (and/or crit) fields in the "Attack" block?  Or maybe can tell me what I'm doing wrong that causes the code to get changed so often? Thanks. 

I add a global damage modifier for sneak attack, you can either just leave it 'on' and ignore the extra damage when not applicable or toggle it on and off as needed if you don't mind the effort.

Another option is to turn the weapon damage type into a clickable button and link it to a macro. Example: this dagger links to a smite macro by clicking on the word "piercing": I like this method because it's in the same spot as the "silver dagger' button to roll the normal damage. You can change the text to say whatever you want, you don't have to leave it as "piercing".

Hm, that's interesting.  How would I do that, andrew?  Would I need multiple macros/buttons for each damage type?

You can also add a button in the description field of the attack, using the format: [Sneak Attack](~charactername|sneak-attack}) where charactername is the character's name, and sneak-attack is a character ability such as: [[ ceil((@{base_level}) / 2) ]]d6 sneak attack damage although in the case above, my sneak attack ability simply called a custom attack called "sneak attack".

Thank you.  I'm going to ask the person playing the rogue if he likes this better than the current method but I think it solves the problem I'm having.  I did make a slight change: I have it roll the sneak attack damage twice in case of critical hit.  So, my output looks like: