Conflict with Polylang plugin causes search to 301 redirect to the homepage

[dennis-n-dean]

Quick summary

If both ActivityPub v7.8.2 and Polylang v3.7.6 are activated, Wordpress search (i.e. example.com/?s=term) 301 redirects to the homepage instead of showing the search page.

Wordpress v6.9

Steps to reproduce

1. Activate ActivityPub v7.8.2 and Polylang v3.7.6 (https://wordpress.org/plugins/polylang/).
2. Attempt to search the site, either using the Wordpress search form or manually by adding /?s=test

Tested with all plugins turned off (search successful)
Only ActivityPub active (search successful)
Only Polylang active (search successful)
Both ActivityPub and Polylang active (search fails)

Site owner impact

More than 60% of the total website/platform users

Severity

Critical

What other impact(s) does this issue have?

No response

If a workaround is available, please outline it here.

No response

[pfefferle]

Oh, that is a weird one! Thanks for investigating @dennis-n-dean !