Got my new wheel all setup, maxxis minion dual ply on stans flows, using stans sealent, yellow tape and a valve. got them inflated with a compressor and seem to be sealed OK, 3 days later and no loss of pressure, from the thumb pinch test anyway, (not had chance to ride the wheel properly yet) but there's spots of clear fluid forming on the sidewalls, almost like the latex is staying inside but the pressure is pushing the water (assuming sealent is water based) thorough teeny tiny holes in the tyre carcass. I've dropped the pressure a bit so it's definitley under 40psi

Should I be worried? Anyone else seen this?

Its fairly common. As the sealant progressively seals the sidewall, this will reduce.

Had clouds/foam coming out of a sidewall of one tyre & it didn't sealed – though I'd used the tyre with tube so wondered if I'd stretch the carcass to much, causing the issue.
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But just re-fitted another used UST tyre (previously used in a UST setup) and the sealant was coming out of holes in the main tread, so deflated it enough for it to stop, left it overnight and then re-filled it with sealant & pumped it back up. Seems fine now, so the first filling of sealant must have affectively sealed up again.

Seems strange to happen on a new tyre though

I'd just ride it – if no drop in pressure I doubt its significant – new tyres on my bikes usually leak a little but I just go out and ride them and the bumps slosh it around inside and seal them better than I could 🙂

I've had seepage through the sidewall of a Nobby Nic UST before. The latex should seal it. Have you been sloshing it around adequately then leaving to settle with the wheel horizontal on a bucket? Then repeat for other side.

Had mine in shed for last six months. Gone flat and won't stay up (same old problem). Any remedy?!

Rip, yeah been doing the rotate shake rotate shake lie on it's side yeah. Seems well sealed but these bit's eepingout very slowly are bothering me. How long should a non-ust tyre with sealent stay up? I know proper ust need topping up more often than tubes but I thought sealent meant virtually no loss over time.

Not IME about the same as any other tubeless setup.