Hello,
Most likely this is due to a firewall causing timeouts. Which coin adapter are you using?
To be clear, does the site become slow when you activate the woocommerce extension? Or the parent plugin?
Most likely this is caused by the parent plugin. If you like, you can also check the Troubleshooting section of the documentation under “When I activate the plugin, my WordPress becomes extremely slow and is unusable.” or “When I activate the plugin, my WordPress becomes somewhat slow but is still usable.” for some thoughts. The documentation is available in the bundle download of the plugin at https://www.dashed-slug.net/bitcoin-altcoin-wallets-wordpress-plugin/
Also this would happen if your server has extremely small memory allocated to WordPress.
Please have a look and let me know if these instructions do not help you.
with regards