I run my UA-1EX with Audacity set at 32-bit floating and it works fine with the UA-1EX set to 44.1kHz and either in its advanced or standard mode. My current understanding is that it is running in 16-bit in both those modes (down to the audio interface s/w used by Audacity, PortAudio: see this long thread from earlier in the year for some background: https://forum.audacityteam.org/t/bit-and-sampling-rates-real-or-imagined/18932/1 ) and Audacity is performing the upsampling on capture. I can’t see the UA-1G manual online but I believe that it is basically a reworked UA-1EX an should work the same.
Have you tried updating to the latest drivers form Roland/Cakewalk - see the downloads tab on: http://www.rolandus.com/products/productdetails.php?ProductId=1089&ParentId=436
Otherwise you’ve got me stumped at the moment.
WC
Note: The reason I have Audacity working at 32-bit so that I get good headroom for editing tasks like Amplification and fades. On export of production files I use Audacity to downsample to 44.1kHz 16-bit PCM WAVs with triangular dithering applied.