It seems you made a mistake somewhere along the line of entering the k-1 and sales info. If the sale was not reported on form 1099-B then the proper way to report the sale in the k-1 sales section is Sales Proceeds $45K Basis of Partnership Interest $45k which results in zero gain thus only line 9 from the k-1 is reported as gain. nothing is separately entered on the 8949.
if reported on a 1099-B, this seems unlikely, then in the sales section of the k-1 both Sales Proceeds and Basis of Partnership are reported as zero and for the 8949 you enter a cost equal to sales proceeds again resulting in no gain
thus the only gain that should be showing is the amount from line 9 of the k-1 that will show on schedule D line 12
several other things make sure to check off final K-1 and full disposition - this is necessary, so any suspended passive losses are now allowed
the k-1 still seems unusual unless its only holding in the year of sale was land. If a building was included then likely there should have been section 1250 recapture
