While rolling again an ability check while under guidance if you fail the first time and you reroll using an inspiration dice, it still said you failed even if you reached the number marked as the DC on the second roll. The number displayed did not change between rolls (no way to know if the guidance bonus changed between).
For example : If the number needed is 12, you roll a 4 on the first try and you reroll the check using an inspiration dice, it will still say the number needed is 12 but you will still fail even if you roll an exact 12.
Also, guidance bonus (1-4) can be guessed by looking at the bonus you have by scrolling over the name of the skill check in the conversation. By reloading the same check and trying it multiple times I found that the bonus displayed is frequently no the real one you have.
For example : While doing a persuasion check with a persuasion check with a base +2 (proficient in persuasion with 10 Charisma), if you scroll over the persuasion option it might say you have +6 (deducing the guidance bonus to be 4) then when attempting the roll the DC is 15. Reloading the same situation, the next time it says you have +4 (guidance bonus might be 2) and this time the DC is set as 12. Something seems to be wrong it might help to separate all bonuses to know where they are from.
A small other point I am still experimenting with is thaumaturgy. Getting advantage on intimidation and performance is cool. After a few intimidation check I absolutely have no idea if it is actually doing anything. It does not appear to change the DC and I did not get a reroll but I might need more experimenting to conclude.