Write a clear guideline, and ask team to follow it.
During the code review, you only ask to stick to guidelines (that everyone agreed on). This way programmers won't feel like your subjective opinion is affecting their work.
Which is why if you have coding guidelines they should be enforced by automated tools. Either the code passes the tool or it doesn't, no on is allowed to nitpick brace placement, spacing, or whatever. Use something like clang-format or whatnot and stick to it.
So we can't tell which party is the problem, and what the issue is and we end up second guessing the person asking the question.
The advice invariably tends towards finding an objective standard so that the person asking the question can check that they aren't the problem person.