I totally agree with headcanoning Jayce as having intense mommy issues and insecure because of his taboo research.
But with how quickly he turned, during his trial when his mom started calling his research crazy, I'm more inclined to think that was the first time she didn't support him. And him storming out, to find someone else who will support him, when "his own family won't ", really sounded like the pout of someone learning for the first time that she had doubts in him. I like to headcanon Ximena as keeping her doubts quiet until his trial.
Personally, I think Jayce was insecure about his research because he already knew not to tell anyone about it. Piltover has an ethos vs magic. He's so Piltoverian, he would know that. I mean, did Cassandra Kiramman even know the details of his research? She said she became his patron because of his extraordinary ambition. Why didn't she say, because his work was revolutionary? If she knew what exactly he was researching, she would've phrased it more specifically than "ambition" (and she still could've retained vague wording, if she found that necessary). That's why I think he was bitter towards Dimitri for doing well in school and able to get his projects recognized. Jayce couldn't get the recognition, because he couldn't tell anyone about his research. But that's just my headcanon.
I just think that Jayce is just too comfortable, going SO immediately for hugs with his mom and with anyone, for me to not believe that Ximena lead him to expect immediate support from her (and the world).
