Mac OS Sonoma features are not working

Was super excited to download and use the new Sonoma OS. However, some of the cool new features seem to refuse to work for my i3 2020 MacBook Air.

1. I tried to use one web app. It worked well for a day after which it started crashing. This is a website that I use on a daily basis for up to 12 hours [to study for an exam].
2. When I use the dictation feature, it works well on my phone, where I can dictate and type, however, on the macOS, every time I touch the spacebar dictation stops.
3. Presenter overlay on zoom does not work, nor does it show up as an option on the menu bar icon.

I'm not quite sure if this is happening with me because of an older model laptop. But if anyone has experienced these issues and managed to fix it, it would be great to know.