3 weeks ago
Recently updated the June security patch, unsure if it's something that coincided with that or it was prior as I use "Hey Google" (now Gemini) on my S23 usually.
However, just now I used "Hey Google" while the S25 was locked, to set an alarm and to my surprise it started playing the audio from the last Video I watched on my phone. Which I might add, wasn't the last thing I did on it either... (Outlook app)
Yesterday, I unlocked the S25, swiped away a Radio App I use frequently (after manually hitting the stop button too), locked the phone and accidentally triggered Gemini (it does it quite a lot) and a few seconds later it started playing the audio from the app I'd swiped away, somehow.
I've had the S25 for a while now (couple of months), but don't have much on it as I still haven't full switched over from my S23, and only recently updated it, so it's had a restart recently.
Even so, playing the audio from something I was recently watching, isn't something I want my phone doing while it's locked... Pretty concerning.
2 weeks ago
Don't find it concerning at all, personally. See if you can tweak so that Gemini doesn't open on your lock screen