Red light can make this tricky, but the meter may not be the only issue. Under strong red illumination, skin tones can appear lighter and lose tonal separation, especially with very diffuse bounced light. That can make the face look "blown" even when exposure is actually close.

With your Sekonic, incident metering using the white dome is usually the better choice here, because reflective/spot metering can be fooled by subject brightness and color. A gray card can help if you must use reflective metering, but incident metering is generally more reliable for unusual-colored light.

Also note that film can respond differently under different light sources, so the practical solution is to test. Meter at the film’s rated ISO, make one frame at the indicated exposure, then bracket several frames over and under. Review the results and use the exposure that gives the best negative for that specific film/light setup.

Finally, the "blown" look may also come from soft, shadowless lighting and focus falling behind the face, not just exposure.