Basically done these quests for him

Azra's Staffs - Retrieve one of Azra Nightwielder's staffs.(6 times)

Experimental Subject - Test out a new spell for Neloth.

From The Ashes - Kill the Ash Guardian Talvas accidentally summoned.

Healing a House - Repair the withered Telvanni tower.

Heart Stones - Find a Heart Stone for Neloth. (8 times)

Telvanni Research - Help Neloth in his research on Ash Spawn.

wind and sand - Retrieve a book about the Alik'r Desert for Neloth

And i have listened to him as he says something along the lines of my steward is missing yet the quest still does not start even through i have done all the things for it. And it didn't realise there was this quest until today so i did the other ones mid way through the main quest and a bunch of other side quests so ideally don't want to revert it back to an earlier a point. Any ideas how to fix it ?

What is the side effect(s) for the experimental subject quest?

As for the missing steward, I got the quest by talking to Neloth after finding a body outside his house...

i willl see if there is a dead body outside and the side effects were it didn't work in water (i think it drained health or stamnia)

directly outside of his house?

i found her she is still alive

yet he says she is missing

Sorry, was reading elsewhere.

Yeah, I came up to the tower, saw her body and went in. Neloth gave me the quest. Maybe mine was bugged and she wasn't meant to be dead yet? And thanks for the tip about the water!

the quest has started now turns out it is because i never talked to her

Awesome. Simple things eh?

yeah thanks for the help it what caused me to go looking for as i just looked around raven rock and it turns out she was just stuck behind the house and i had never talked to her