Siril Scripting (any_allowed_extension) Filenames

I’ve had trouble working with filenames and siril script failing. I am hoping to keep the exposure in the filename but the script fails when reading the master calibration frame if a period is included. The file name being (Flat_1600gain_10.21s_stacked.fits) When I remove the period in the 10.21 it works fine. The (any_allowed_extension) leaves me to believe this should work! any ideas?

Reading FITS: file Flat_200gain_10.21s_0001.fits, 1 layer(s), 6036x4036 pixels
11:19:29: …/bias/Bias_1600gain_10.21s_stacked.[any_allowed_extension] not found.
11:19:29: Error in line 17: ‘preprocess Flat_200gain_10.21s_ -bias=…/bias/Bias_1600gain_10.21s_stacked’.