I cannott reproduce that behaviour, at least here. One possibility is that the problem does not exist in R2024b, and that upgrading could solve it. The other option is to change the figure Position property without altering the axes Position property.
I experimented with that here, although since the problem is not present, I cannot determine if the result is effective.
figure, imshow(0.7*ones(100)), title('Test1')
figure, imshow(0.7*ones(300)), title('Test2')
figure, imshow(0.7*ones(500)), title('Test3')
hf = gcf; % Figure Handle
pos = hf.Position % Get Figure Position
hf.Position = pos + [0 -100 0 100]; % Change Figure Position
pos2 = hf.Position % Check Result
.
