Reported as DevCom-1592387 by Christopher Dannemiller:

When values are converted from string to a floating-point at the exact rounding boundary, the resulting values in the compiler and std::from_chars are incorrect. Since there are a large number of values, ~8million on the positive side, that have this problem, I have only included one example:

131071.98828125f, this should result in the floating-point value 0x47fffffe stored in hex. However, MSVC v19.29 gives 0x47ffffff. This can be explored using the following Godbolt link https://godbolt.org/z/r7Ks9GMEb. MSVC v19.28 and earlier, along with GCC and Clang, provide the correct results. This indicates that this is a regression in the compiler.

Also tracked by VSO-1441452 / AB#1441452 . We'll need to inform the UCRT and compiler when we have a fix.