This is caused by single_tag: true being specified - only edits where mw-undo is the only tag are counted. While this makes sense generally, the PHP7 tag should be ignored for all automated edits, not just undo

The relevant code:

if ($this->usesSingleTag($project, $tool)) {
               // Only show edits made with the tool that don't overlap with other tools.
               // For instance, Huggle edits are also tagged as Rollback, but when viewing
               // Rollback edits we don't want to show Huggle edits.
               $condsTool[] = "
                   EXISTS (
                       SELECT COUNT(ct_tag_id) AS tag_count
                       FROM $tagTable
                       WHERE ct_rev_id = revs.rev_id
                       HAVING tag_count = 1 AND ct_tag_id = $tagIds
                   )";

Different sites have different ids for the new PHP7, so it may need to be filtered based on the change_tag_def for each site

CC @MusikAnimal, who may have a better implementation idea

Ah, see DannyS712 already identified the issue with single_tag (thank you!). I saw this task via email when it was still under the old title :) Anyway, this is pretty complicated, so don't expect a quick fix.

In T229387#5384439, @MusikAnimal wrote:

Ah, see DannyS712 already identified the issue with single_tag (thank you!). I saw this task via email when it was still under the old title :) Anyway, this is pretty complicated, so don't expect a quick fix.

Thanks @MusikAnimal and @DannyS712