Suddenly Glibc 2.39 lost the `fmod' function for i686 :(

Yesterday my GNU Guile build failed with the "libguile/numbers.c:728: undefined reference to `fmod'" message.
And after spending some time in research I found that there's no build misconfiguration, nm just does not find `fmod' in /usr/lib/libm.a

And it seems that's I'm not the only victim: https://bugs.launchpad.net/ubuntu/+source/glibc/+bug/2036283

Now I wonder where did it go and why the issue is reproducible on i686 only

#glibc