[סגור] Severe performance regression after updating WPML — DB CPU spikes & resource usage ~2x

Background of the issue:
We run a multilingual WordPress site with WPML. Right after updating WPML (core + String Translation + Media) to 4.8.1, our total server load roughly doubled. PHP-FPM and MariaDB CPU spikes appear during normal page views and especially when switching languages or rendering pages with many translated strings.

Symptoms:
Overall CPU and DB usage approximately doubled compared to pre-update. TTFB is noticeably worse, and random requests stall while MySQL shows long queries.

Questions:
What could be causing the severe performance regression after updating WPML to 4.8.1?
How can we resolve the increased server load and CPU spikes after the update?