Rumor has it that CO2 might freeze the sealant and render its usefulness less than, er, useful. Also the pressure generated by the CO2, rather than a more benign hand pump may have blown the sealant out. I’m sure I will hear about my theories. Don’t use Stans, use Orange. Stans is find for mountain bikes at lower pressures.
When your sealant isnn’t working, you will need to insert a tire ‘bacon’ or similar, into the hole to seal it up. I have run 1500 miles on a tubeless with a bacon plug. Just look up tubeless tire plugs. If you use one of those then I would think CO2 would work fine.
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Road 🚴🏾♂️ & Mountain 🚵🏾♂️