Since 2.5, existing translation from sources were loaded as alternative translations.
While it preserves existing translations, it had the big issue of preventing having the benefits of auto-propagation.
The way existing translations are loaded has been changed in the following way. This applies to all bilingual filters (PO, Okapi TTX, etc.).
For a given source segment, if there is no existing translation in project_save.tmx.
The translation is loaded as a default translation, except in the following case.
If the same source segment has already been found in the source documents, but with a different translation, the new translation is loaded as an alternative.
The result will thus depend on the order in which order the source segments are loaded.
All translations from source documents are also displayed in the Comment pane, in addition to the Match pane.
Another change has been made specifically for the PO filter.
When a fuzzy translation is loaded, the fuzzy mark ([PO-fuzzy]) is no longer loaded as hard-coded in the source segment (as a crude way of giving a penalty to the match), but is loaded with a 20% penalty applied (i.e., a 100% match becomes an 80% match). The word [Fuzzy] is displayed on the source segment.