I did not download your spreadsheet. You can use these instructions to convert the output from PROC IMPORT into data step code we can use.
Most likely, there is a non-printable (invisible) character(s) in F1 and thus the contents of F1 cannot be converted to a number. You can use the COMPRESS function to remove characters you don't want, or keep characters you do want. In this case, we want to keep digits, the dot, and possibly commas and a hyphen to indicate a negative number. So this will do the job:
data want;
set have;
f1_numeric=input(compress(f1,'.,-','dk'),best32.);
run;
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