Some wall tiles in a shower in a loft conversion bathroom have cracked. The tiles have been up for about 2 months. The shower has been used only for the past couple of weeks. Flexibond adhesive/grout were used. The tiles are Fired Earth Architecture tiles. Just wondering whether it's normal for such cracks in tiles and grout to appear. The builder says yes.

We would need more info than that. What sort of tile. What substrate, make of adhesive, what prep work was done, where are the cracks ?
Photos will help too but you will have to register i believe to post pictures.

some fired earth tiles are prone to crazing in the glaze but not cracking

tiles and grout cracking in a shower enclosure is as much use a chocolate teapot, stop using your shower as water ingress can cause a lot of damage to the rest of your house

your builder is taking you for a fool, without knowing how the shower enclosure was constructed its difficult to advise

do you have more info please

A lot more info required

Agree with above, especially 'stop using the shower until it is sorted'
Give us as much info as possible. Most of your loft conversion material is probably timber and this is prone to movement as it dries out. This is one possible explanation but for tiles to crack after 2 months is quite severe movement.

no tiles should be cracking after 2 months,if they are then someone is at fault,i would speak to the builder immediately and get this sorted out

as above posts, and I'd be worried if your buider thinks cracking tiles are the norm