R-style code cells without comment are not parsed properly (first line is skipped)

[smathot]

When pressing F9 while the cursor is on the print(2) line, print(1) is not selected (i.e. not recognized as a code cell).

# %%
print(1)
print(2)

When the code cell includes at least one comment line, this does not happen.

# %%
# Comment
print(1)
print(2)