I bet the problem is with the lender.
I had difficulties with a survey buying my house many years ago (chain free). It was over a question of whether subsidence claims would be met, due to a willow tree which my independant arboriculturist stated in writing, was too far from the house to present a problem. This came about after an ssue was flagged by my lender's surveyor.
This all happened because I had paid for a buyer's report and had hassled the lender due to a long wait getting a surveyor to site. Eventually this was arranged, but the estate agent told me on the agreed date that the surveyor had picked the keys up after it had got dark. I then asked the lender how the surveyor could prepare a report on the exterior of a building, without actually seeing it! Subsequently, a second visit was arranged by the lender whereupon the disgruntled surveyor flagged a "non-problem", i expect out of spite. We had been seriously dicked about and several weeks were lost due to the lender who were particularly casual and unresponsive to their customer!
The lender was non-commital about the question of subsidence claims being met, despite the professional report which I had sought and at the recommendation of their own surveyor's report. This wrangling went on for a whole month at which point we got fed up with their nonsense, so i asked my mortgage broker to find a different lender. It was a pleasure telling the first shower to stick their loan where the sun don't shine. 😀
A new lender was sought and found the same day and they sent a surveyor the same afternoon! No problems were found with the property and exchange took less than two weeks from the first call from the bank. We had moved in a month later.
ALL our troubles were caused by the bank!
Good luck!