Hi Jarrah, does your grill top light o.k.?
Could be worn piezo, grill top lid has a safety switch when you open the grill lid, this allows the gas to pass thru.
If you have a 3 way fridge does it work on gas?
Could be a faulty or partly clogged gas regulator at the bottle.
To ignite our oven, we have to open the cover over the hot plates. When closed, the cover has a cut-off device for gas to the stove unit.
As Peter has stated, often it takes longer for gas to reach the oven. We make sure gas is at the stove by igniting a hot plate first, then we know that gas has reached the stove at least. Then it can take a bit longer for the oven to ignite.