Hello Goldilockers,
I have noticed that with our weak southern winter sun my pillows are looking decidedly limp. Even with the cloudy days and blessed rain the few patches of sunlight are not doing the same job as a belting hot summers day.
I guess this is one of the reasons that KapoK is so commonly used as bedding material around the equatorial belt of our amazing planet. Where something grows naturally is often the place where it functions or gives forth its best qualities.
Do not despair, come spring and summer, our pillows and mattresses will spring to life again.
Be patient, stay well, sleep well. Blessings Julie