I was playing one of the events and noticed my Tender Wildguide was unable to use it's tap ability to add a +1/+1 counter. on my next turn I noticed that it'd highlight 2 lands when going to use it's ability, but when I actually used the ability (on my turn), it didn't tap the lands or use any mana. this problem doesn't happen on the offspring token.

what seems to be happening, after a few tests, is that the game is reading the offspring price as a price for the tap abilities, even though I'm assuming that's not intentional, but also not making the player pay said cost. this bug can be recreated just by having a tender wildguide on the battlefield. if you have 2 mana open, you can activate it but won't spend the mana. if you have no remaining mana, it will not let you activate it, and will go through opponents phases not giving you the chance to activate (if you have no other instant speed responses that is).

I'm not sure if this effects other offspring cards or not, as I haven't been able to test them, but I'm guessing there's a possibility.