I have also seen that this happens not only with Tamiyo, but also with Tasha, Unholy Archmage's "until your next turn" ability as well. See attached screenshots.
Update:
This bug applies to a bunch of other abilities of the form "until [time limit], whenever [condition], [effect]". You will "keep" the triggered ability until the next time the [condition] is met, even if the [time limit] has already passed.
A non-exhaustive list of cards I have observed that this issue affects: Dovin, Grand Arbiter; Mistway Spy; Davriel, Soul Broker; Tamiyo Meets the Story Circle; The Mirari Conjecture; Jace Reawakened
This issue does not seem to happen for abilities worded like "whenever [condition] this turn" like Harald Unites the Elves, The Bloodsky Massacre, or First Day of Class.
Additionally, I noticed while testing this that if you ultimate Jace Reawakened, you will only copy the first spell cast, then "lose" the ability from the ultimate even though the card says otherwise.
I have also seen that this happens not only with Tamiyo, but also with Tasha, Unholy Archmage's "until your next turn" ability as well. See attached screenshots.
Update:
This bug applies to a bunch of other abilities of the form "until [time limit], whenever [condition], [effect]". You will "keep" the triggered ability until the next time the [condition] is met, even if the [time limit] has already passed.
A non-exhaustive list of cards I have observed that this issue affects: Dovin, Grand Arbiter; Mistway Spy; Davriel, Soul Broker; Tamiyo Meets the Story Circle; The Mirari Conjecture; Jace Reawakened
This issue does not seem to happen for abilities worded like "whenever [condition] this turn" like Harald Unites the Elves, The Bloodsky Massacre, or First Day of Class.
Additionally, I noticed while testing this that if you ultimate Jace Reawakened, you will only copy the first spell cast, then "lose" the ability from the ultimate even though the card says otherwise.