Resolve Slow WooCommerce Checkout Bug

The checkout page on my WordPress + WooCommerce store hangs indefinitely—orders can’t be completed and the entire site feels sluggish. No new plugins, updates, theme tweaks, or custom-code edits have been made, and no error messages surface; the spinner simply spins.

What I need is a clear diagnosis of whatever is blocking the checkout request and a solid, permanent fix that brings page-load times back to normal for the whole site.

Key deliverables
• Identify the bottleneck (database query, API call, payment-gateway script, server misconfiguration, etc.).
• Apply the fix and prove that the checkout completes without delay.
• Optimise overall site performance (cache settings, asset minification, image/compression tweaks) so pages load fast across the board.
• Provide a short summary of the root cause, steps taken, and any recommendations for future maintenance.

Please work safely on a staging copy or create one if needed, keep WooCommerce transactions intact, and ensure no data loss while you troubleshoot.