uneven taxonomy and OTU table length after filtering

Thank you thermokarst,
I realized from the help message that I put wrong output command. It should be "--o-collapsed-table" Now the problem is solved.
I was looking at this question while I tried to solve the question. The output command in this question is wrong too (It has the output as visualization)....How to add taxonomy to feature-table.qza and get otu id of each taxonomy and number of otus