I swear by fairy pods & fairy softener! I even use it for myself & partner now. Highly recommend x
I'm using fairy pods and softener also fairy boosters. I've used these since my little girl was born and never had any issues xx
Could it be detergent or limescale build up in the washing machine? Thats especially common in hard water areas I would try running a maintenance cycle if you haven't already (if your washing machine doesn't have a specific option then pick the hottest cycle, can also put some white vinegar in the drawer)
I’ve been using Fairy liquid pods and also the softener. Can’t say I’ve had any issues so far