Cutadapt demultiplexing with mixed primers

Dear sir
I have a problem in dealing with paired-end 16S rRNA amplicon sequencing data with q2-cutadapter as described in Import multiplexed R1.fastq and R2.fastq with mixed forward and reverse reads + truncate reverse primer . One sample have two files .R1 &.R2, however, both of them have mixed-up sequences, that is R1 and R2 files both have foward-primer+sequences and reverse-primer sequencs. I don’t kown how to deal with those data with q2-cutadapter.