^To his point, if you intend to diagnose this for free with help from your internet friends (nothing wrong with that, it’s a great resource and convenience of this 21st century technology) then you need to help. IE see how repeatable it is. Same conditions different conditions. You’ve added nothing other than it did it twice, in a row and then you apparently parked it. And a buddy looked underneath and said nothing looks broken.
It doesn’t feel unsafe to drive and you’ve also confirmed that it drives fine.
So please go try to repeat the condition. Pay attention to all parameters. Does it do it cold, or only after up to temperature, or directly coming off of a highway speed run, etc.
We’re trying to help but this is not the time to be of few words.
And while possible it’s something structurally wrong or something worn out. It’s highly unlikely given the age and extremely low miles. (Which some of the respondents aren’t considering).
Oh also, brake system. Is it just a standard vac or hydro boost? Not electric over hydraulic? Presume so since it’s a class 4 chassis (or 3 can’t remember if you said 350 or 450). Also unlikely but throwing it out there
