Gerrit sometimes doesn't show intra-line diffs

E.g. https://codereview.qt-project.org/c/qt/qtbase/+/497247/5/tests/benchmarks/corelib/io/qdir/10000/tst_bench_qdir_10000.cpp looks like this:

Expected: the const in the first line is green, while the rest of the line is light-green, and similar for the other line.
This is another file in the same patch set (https://codereview.qt-project.org/c/qt/qtbase/+/497247/5/tests/benchmarks/corelib/tools/qhash/tst_bench_qhash.cpp)

It seems to be rather random when this happens, and if it does, it makes reviewing much harder.

Is there some limit that's being hit? If so, can it be increased, please?