I have a player I am trying to help in my game. They have Mark of Sentinel and Potent Dragonmark feats selected and on their character sheet. Wisdom is selected for the Potent Dragonmark stat, but it does not adjust in their Wisdom total (Mark of Sentinel does). It also does not add the spells from Mark of Sentinel to their list of prepared spells, as it should once they select Potent Dragonmark. Am I doing something wrong or reading it wrong?

Thanks for any suggestions.

I don't think you're doing anything wrong or reading anything wrong. The Potent Dragonmark feat is not working properly right now; people have reported a variety of issues with it in the support thread for the new release. 

Unfortunately, since it's a holiday weekend in the U.S., we're not likely to see any further fixes for any of these issues until at least Monday.

Thanks. That is helpful to know.

I am only commenting to say that I am experiencing the same issue. The Ability Score Increase and Always Prepared Spells and not be granted from Potent Dragonmark.

In the interim, I've just been making specific Homebrew versions of Potent Dragonmark when my players take it. Currently, I've only done it for the Mark of Healing (cannot share because of licensed content), but here's what I'm doing in case it's helpful to others:

• Create the feat from scratch - copying a Dragonmark feat seems to come with a built-in choice for stat that does nothing and there's no way to delete it (or suppress it by setting the number of options to 0) because there aren't actually options.
• Create a version for each mental stat--this is important so you can set the correct stat for the spells.
• Copy the text from Potent Dragonmark into the Description.
• Add a prerequisite for the dragonmark feat being replicated (e.g., Feat - Mark of Healing)
  • Example Text "General Feat (Prerequisite: Level 4+, Mark of Healing Feat)"
• Add the stat increase (Modifiers -> Bonus -> <Stat> Score, Fixed Value: 1)
• Add each spell to the list with the chosen stat set. Unfortunately, these spells will show up as at-will because you cannot add always prepared spells through a feat with the current system (I believe it is currently limited to homebrew subclasses and species). I include a note that they "require a spell slot" in the additional description.
• Add an Action:
  • Action Type: General
  • Name: Potent Dragonmark: Dragonmark Spellcasting
  • Activation Type: Special
  • Reset Type: Short Rest (set Limited Use to 1)
  • Snippet: You have one extra <strong>level {{(characterlevel/2)@roundup,max:5}}</strong> spell slot to cast the spells granted by your Dragonmark feat. You regain the expended slot when you finish a Short or Long Rest. You can use this spell slot to cast only a spell you have prepared because of your Dragonmark feat or the Dragonmark Preparation benefit of this feat.
    • This will provide the text for your character sheet to indicate the level of the spell slot.
  • Description: You have one extra spell slot to cast the spells granted by your Dragonmark feat. The spell slot’s level is half your level (round up), to a maximum of level 5. You regain the expended slot when you finish a Short or Long Rest. You can use this spell slot to cast only a spell you have prepared because of your Dragonmark feat or the Dragonmark Preparation benefit of this feat.
• Create additional copies of the feat, adjusting the stats.

yeah right now feat seems still be not working theres a few post on it now including my with no solution solved yet besides making a homebrew version of the feat thats at least a simple yet tedious fix but it works just fine enough!

It wasn't fixed this weekend because the devs have weekends off.