Shared ownership advice on revaluation

[Zia321]

We live in an end of terrace 3 bed shared ownership with a good size garden. After a long process we are nearing towards exchange and completion. Our valuation ran out so we had to get it revalued (its original value was November 2019) our surveyor knew we were nearing completion and valued our property the same price as he did back in November 2019, because we already had a buying sold at that price.
We felt back in November he undervalued because a property similar to ours sold for the same price on a smaller plot but we just went ahead.

However our neighbour that is also shared ownership, two doors down has put their property on the market today. It's a mid terrace with the same specification but smaller garden and smaller plot.

They have had a valuation for the exact same price as ours, and have placed it on the market for that price.
We are selling it through the same housing association and can not change the price it has been valued.
We both bought out properties as new builds and I paid premium for mine because its an end of terrace on a larger plot.

I have booked in with our neighbours surveyor to have our property valued, however the housing association are saying we should go with our original valuation as that's the price our buyer agreed and has a mortgage in place for, which would mean we would be selling at a loss.

What would you do? Advice please?

If you can’t change the valuation price is there any point in getting a second opinion? Do you think there would be a big difference in valuations?
Would you re-market it if the buyer pulled out? It’s hard to guess where the market will go with coronavirus as well, you could get stuck if they do pull out. On the other hand there could be more demand for shared ownership. You don’t have a crystal ball at all do you?

I don't see why we can't get it revalued as we are the ones paying for it. I think there will be a big difference in the valuations.. Unfortunately our original surveyor is refusing the adjust the price.

There was a huge demand for our shared ownership house and buyer was found first day it went live on the market. The reason the sale has taken so long is that our purchase property fell through and the housing association were incredibly slow at getting the buyer approved.