Inconsistent Page Speeds

https://portlandcards.com/

### WordPress Environment ###

Home URL: https://portlandcards.com
Site URL: https://portlandcards.com
WC Version: 2.6.11
Log Directory Writable: ?
WP Version: 4.7
WP Multisite: –
WP Memory Limit: 512 MB
WP Debug Mode: –
WP Cron: ?
Language: en_US

### Server Environment ###

Server Info: Apache
PHP Version: 5.6.29
PHP Post Max Size: 128 MB
PHP Time Limit: 300
PHP Max Input Vars: 1000
cURL Version: 7.36.0
OpenSSL/1.0.1e

SUHOSIN Installed: ?
Max Upload Size: 128 MB
Default Timezone is UTC: ?
fsockopen/cURL: ?
SoapClient: ?
DOMDocument: ?
GZip: ?
Multibyte String: ?
Remote Post: ?
Remote Get: ?

### Database ###

WC Database Version: 2.6.11
: 
woocommerce_sessions: ?
woocommerce_api_keys: ?
woocommerce_attribute_taxonomies: ?
woocommerce_downloadable_product_permissions: ?
woocommerce_order_items: ?
woocommerce_order_itemmeta: ?
woocommerce_tax_rates: ?
woocommerce_tax_rate_locations: ?
woocommerce_shipping_zones: ?
woocommerce_shipping_zone_locations: ?
woocommerce_shipping_zone_methods: ?
woocommerce_payment_tokens: ?
woocommerce_payment_tokenmeta: ?
MaxMind GeoIP Database: ?

### Active Plugins (29) ###

amr shortcode any widget: by anmari – 3.3
Auction Nudge: by Joseph Hawes – 4.4.2
Autoptimize: by Frank Goossens (futtta) – 2.1.0
CM Registration: by CreativeMindsSolutions – 1.5.1
Duplicator: by LifeInTheGrid – 1.1.26
Font Resizer: by cubetech.ch – 1.3.5
IM WooCommerce Account Widget: by Fabio Folcio – 0.4.0
Instant Gzip compression: by RiotWeb – 2.0
Lazy Load: by  – 0.6.1
Loginizer: by Raj Kothari – 1.3.2
Modular Custom CSS: by Nick Halsey – 2.0
P3 (Plugin Performance Profiler): by GoDaddy.com – 1.5.3.9
Stripe Payment Gateway for WooCommerce ( Basic ): by ExtensionHawk – 1.0.8
Podamibe Simple Footer Widget Area: by Podamibe Nepal – 1.1.2
Regenerate Thumbnails: by Alex Mills (Viper007Bond) – 2.2.6
Search By Product tag - for Woocommerce: by Matthew Lawson – 0.3.1
Storefront Top Bar: by Wooassist – 1.0.1
Ultimate Form Builder Lite: by AccessPress Themes – 1.3.1
Ultimate Member: by Ultimate Member – 1.3.78
Woo Product Remover: by Mohammad Farhat – 1.0.0
WooCommerce Category Accordion.: by TechieResource – 1.2.1
Woocommerce CSV Import: by Allaerd Mensonides – 3.3.0
WooCommerce Extra Product Sorting Options: by SkyVerge – 2.5.0
WooCommerce Grid / List toggle: by jameskoster – 1.1.0
WooCommerce: by WooThemes – 2.6.11
Yoast SEO: by Team Yoast – 4.0.2
WP Custom Register Login: by Jenis Patel – 2.0.0
WP-Optimize: by David Anderson
Ruhani Rabin
Team Updraft – 2.1.0

WP Super Cache: by Automattic – 1.4.8

### Settings ###

Force SSL: –
Currency: USD ($)
Currency Position: left
Thousand Separator: ,
Decimal Separator: .
Number of Decimals: 2

### API ###

API Enabled: ?

### WC Pages ###

Shop Base: #7 - /
Cart: #83 - /cart/
Checkout: #84 - /checkout/
My Account: #824 - /my-account/

### Taxonomies ###

Product Types: external (external)
grouped (grouped)
simple (simple)
variable (variable)

### Theme ###

Name: Storefront Child
Version: – 0 is available
Author URL: 
Child Theme: ?
Parent Theme Name: Storefront
Parent Theme Version: 2.1.6
Parent Theme Author URL: https://woocommerce.com/
WooCommerce Support: ?

### Templates ###

Overrides: storefront-child/product-searchform.php version - is out of date. The core version is 2.5.0
: Learn how to update outdated templates

The problem: Myself and others have independently checked the site speed over multiple devices and ISPs, and we are getting server response times of 5-8 seconds, 4 seconds for page to fully load, and searches taking between 5-12 seconds depending on the amount of results.

I first contacted my hosting provider, namecheap, and they said my site speeds were very good (0.5 seconds to connect to server, 4 seconds to fully load page). And I received good scores from gtmetrix (around 90-96%/100%).

But my google page insight results are varying greatly when testing back to back. I’m getting results between 33-77/100 on mobile and between 40-92/100 on desktop. When the scores are low, the number one suggestion is to improve server response time.

I’ve taken all the steps I could find on improving speed, and have seen good results, but I think there is more that needs to be done. If anyone knows what the problem might be or how to fix it, I would be greatly appreciative. Thanks! -Dean