Matomo creates duplicates for the custom dimension values containing spaces: one with ' ' and one with '%20'

We have a custom dimension ‘Studio’ to tag customers on our website. Some customers have a space in their ‘Studio’ dimension, e.g. ‘Black eagle’.

For some reason, Matomo displays 2 versions for every dimension instance with a space:
“Black eagle” and “Black%20eagle”.

Duplicates are in the visitors summary for our custom dimension: Visitors >Studio. Duplicates are also in the segment builder.

The analytics, e.g. the number of visits, for each separate duplicate is identical and correct, but if I build a segment by combining both of them with “OR” condition, then I get some crazy number, e.g. 46 correct visits against 157 when I use both duplicate values.

This looks like a bug in Matomo. Is there way to eliminate the duplicates?