Google is once again testing a larger font size in the search box in the mobile search results. We saw this back in 2021 with the mobile search box, also in early 2022 with the desktop search box and then several other times over the years.
This new one was spotted by Brodie Clark, he posted these screenshots on X - I made them into a GIF so you can see it:
Here is the normal font:
Here is the larger font:
Forum discussion at X.
