Need help with beams

I have groups of triplets in 12/8 time in the form of eighth-eighth rest-eighth (see attached excerpt). Musescore automatically enters the two voiced eighths with flagged stems, but I would like a beam across the group of three in order to make the triplets more apparent. I am able to do this for the first triplet, but when I try to do it to successive triplets, it places the beam across all the notes, as shown in the second measure. I have even tried copy and paste of the first triplet, but it will still extend the beam all the way across. I have also included an example of real music that uses just the form I am trying to achieve.