Sometimes you can fix them by loosening the nut, giving the valve a push/wiggle and tightening it again, then try and get the sealant on it by holding it valve down then flipping it over quickly. No guarantees but worth a quick try.
Thanks. Went for a full retape for my sins.
@snoops started
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Sometimes you can fix them by loosening the nut, giving the valve a push/wiggle and tightening it again, then try and get the sealant on it by holding it valve down then flipping it over quickly. No guarantees but worth a quick try.