I see a few problems with your string. A simple problem is your title search. It starts TI=(keyword1) . . . The closing of that parentheses signifies that your specification of the title is complete. What you have after it is not part of the title limitation.
In the text you say you are looking for
the said document contains in its title, a keyword3 followed by one word and then a keyword4.
To look for that you might use TI=(keyword3 ADJ/2 keyword4)
It would find keyword3 blah keyword4 and would also find keyword3 keyword4 since a distance of 2 is not exactly 2 but within 2.
When I build up a large Boolean search string (almost never in google patent search) I build it in pieces that I try separately and put it together in a text editor. It is very easy to make a mistake and have a search that isn't searching for what you think it is searching.
One issue with google patents is that it is often forgiving, like google searching, and finds what you are looking for even if you spell it wrong. In this context, I find that it often returns things that do not actually meet my Boolean search criteria. If you want keyword1 to be taken literally you need to use “keyword1”.
This looks like you are experimenting with the Boolean capabilities looking for something you know is there rather than doing a prior art or freedom to operate patent search. That can be a good way to learn boolean searching but does not exercise patent searching skills. For example, one would normally not put much weight on the detailed wording of a title.
You might investigate other free patent search engines like Lens, formerly called "The Lens". It is more careful and precise with Boolean searches.