How red flaggy is this? I need some secondary opinions.

I'm vetting someone I've been chatting with off and on for about 3 months, we've just started a "trial" of a week

Things of note: - I'm audhd and have been clear and specific - I'm married, but my SO is aware, encouraging and we're only open for me to have a Dom (they don't want the kind of dynamic I do, we tried, unsuccessfully) otherwise I have a very happy marriage. - we are online/ldr - I have pretty bad rsd that can be triggered by extended silence/unresponsiveness. I know this and just ask that if possible, let me know they are busy so I don't expect responses.

So yesterday the Dom I'm vetting went radio silent for over 8 hours. They have been exacting and given me "shit" if I'm not checking in regularly. I did reach out over that 8 hours and message to try and start some conversation. I was met with silence for another 5 hours. On previous days it's been 4 or 5 hours of radio silence.

So I asked bluntly if they are cheating on their spouse. I don't like cheaters and have a strong sense of morality. They side stepped it saying it's not the same as with my husband. And got all offended and upset that I asked. And said they were bothered that I asked. :/

They then said they needed space to consider if they could be in a dynamic with me. I'm hurt. I haven't hid anything. So I'm wondering if it's a red flaggy as I'm seeing and if I should call it now. I get that people have lives etc outside of things, but 8 hours of absolutely nothing? Feels wrong to me. It takes 10 seconds to send a message that they are busy and will be around later.

If there's any details missing, ask away, as I'd really like some outside opinions on this.

*** editing to update*** we've decided to pull the plug. They can't cope with my audhd and I can't cope with the lack of transparency.