I have been using this tag for years and only noticed that it leaves a rogue percent character ‘%’ afterwards.
I think this has been like it for a while looking back to last years weather reports that I have logged.
e.g.: 11:43 12/06/19%
Confirmed, just tested in 10.37.S93
12:12 pm 06/16/19%
fixed , latest .zip update, also %maxsolarweek% had same problem
Good deal 
Nice one thanks.