Is UK immigration sensitive on visit length? In the first application we said a trip of 3 months was planned, in the 2nd application 2 months, they highlighted this on the 2nd refusal letter. This for a Visit visa.

Very much so......please remember that you need to prove that your spouse intends to return to Thailand. Generally, this will be returning back to work. I note from your previous post your gf does not work or have assets. In my opinion this will make a visit visa very difficult to get I'm afraid. Have you thought abour a fiancée visa? Appreciate you would need to return on your own first to meet the criteria but might be a better option. 

 

I had to leave my wife in Thailand whilst I came back and got a job and accommodation etc. However, once this was done the visa was relatively straightforward. 

I wouldn't say that the ECO's are necessarily sensitive about the overall length of the proposed visit but it is certainly a factor, you say that the decision maker highlighted the length of the visit in the refusal letter when your girlfriend applied, what did they actually say to her?

Keep in mind that you don't have to satisfy the decision maker about anything, your girlfriend is the applicant and it's her that needs to satisfy the ECO that her proposed visit is genuine, affordable and that, on the balance of probabilities, she will leave the UK at the conclusion of her trip.

As the previous poster has indicated it's going to be very difficult for an applicant with no money, no job or seemingly no real ties to Thailand, to satisfy the decision maker that she would leave the UK at the conclusion of her visit.
It would be helpful if you could post the actual reasons for the refusal, leaving out any personal details.

First mistake was applying for 3 months on a first application.

 

Second mistake was going for 2 months on the second application...

 

Sight of the refusal letters would give a much better idea of the real reasons for declining. The failure has much more to it than the length of visit !!

 

 

Not having a job to return to is not an issue as long as there are other valid reasons to return i.e land or property ownership.