m0useanswered grow question 1y ago not a problem, pressure differences will cause the fan to die faster but some amount is expected.
When the tent is "sucked in" its under negative pressure, this is good for keeping smells inside the tent as it means the pressure is always lower in the tent and smells can not escape as the outside pressure is higher and always moving into the tent to equalize it. If it was under positive pressure it would look bloated, but you would need air pushing into the tent to get that vs sucking it out. Slight negative pressure is good. keeps the air moving and smells trapped. Slight positive pressure is not really needed. it allows smells to escape.