I've been reluctant to comment on this Brexit issue because the entire situation seems so ridiculously convoluted and confusing, and because I'm not a British resident familiar with the nuances.
Although I was born, raised and educated in England, I left the country long before Britain became a member of the EU, finally settling in Australia around 1972 because I preferred the weather, the more laid-back and egalitarian society with less strict rules, the closer proximity of Australia to Asian countries such as Thailand where I had lived and worked in my early 20's, and so on.
However, it has occurred to me that a more serious problem than the Brexit issue, is
the apparent inability of the British political system to implement the outcome of their own referendum. In other words, the confusion and never-ending delays and disagreements preventing an amicable Brexit solution, is an indication that the political system and rules regarding referendums in the UK need to be changed.
The referendum procedures are flawed. My advice to the UK would be, first change the rules regarding referendums so that the outcome will be clear and unambiguous, then hold another referendum on the Brexit issue.
In the Australian system, those voter results on the Brexit referendum would not have been considered a sufficient majority. Our standards are higher.

In Australia, in order for a referendum to succeed,
a double majority is required. That is, a majority of the total votes throughout the country is required,
in addition to a majority vote in the majority of the states. We have 6 states in Australia (although one of them is described as a Territory). Not all states have similar size populations, so in a referendum it would be possible for there to be a significant over-all majority, say 65%,
which would, however, not be sufficient if 3 out of the 6 states voted against the referendum.
As I understand, the UK has 'effectively' 4 states which have at least some of their own administrative powers within the system; England, Wales, Northern Ireland, and Scotland. Only England and Wales voted to leave the EU, (2 out of 4) and the over-all majority throughout the UK was quite small at 51.9%. That's the problem.