Failed roast potatoes. Have I lost it?

[PollyOrange]

Done roasties on Christmas Day and also the week before and both batches weee awful. I've previously been good at roast potatoes but no more.
Maris piper potatoes. Par boiled for 15 mins from cold water. Mix of olive and rapeseed oil. (No animal fats ). The oil was hot or so I thought. Oven 180 fan. They just didn't seem to sizzle or crisp up no heated oil up and put more on but only a few were crispy.
Could they have been crowded ?
Ideas welcome please. I feel scared I've lost it.

I had this on Christmas Day when despite doing everything exactly as I do every week they wouldn’t crisp…my mash then wouldn’t soften when I was boiling it and i read that it could be a result of acidic potatoes and to salt the water more which worked for the mash but my roasts were already in the oven.

Those roasties in your photo look really good!

Welcome back to potatoes with Polly. Here's this week's pic. Boiled for slightly longer and fluffed and left to cool for a bit before roasting. First pic is during and second is after

And for anyone thinking there aren't as many on second pic it was because I had a "starving " DS who wanted to eat urgently

Oh those look perfect!

@soundsys thanks. They're getting there. Need a new pot of marmite as I realised mine is gluten tainted potentially so that next

Contrary to other posters I have never par boiled my potatoes and mine are always lovely and crispy on the outside.

Looking good

I've gone back to using lard for my roasties, they always turn out crispy with a fluffy middle. I melt my lard on oven tray while potatoes are par boiling, toss potatoes in it after steam drying them, season. For a change if I'm doing them to go with steak, I roast garlic & add chopped onion to the potatoes in the oven, then add chopped Rosemary or thyme towards end of cooking time.

@PollyOrange surely marmite is full of gluten?! It's made from an extract of brewers yeast? 😂 have they managed to make it gluten free??