Reproduction steps:
1. Open user's attached project in "XmlSerializers.zip"
2. Make sure the iOS device you will be using is connected to the internet
3. Build and Deploy the project to the iOS device
4. Press "load xsd generated" and wait for the load time to be displayed

Expected result: Load time will be ~300-2000 milliseconds
Actual result: Load time is >10000 milliseconds

Reproducible with: 2019.3.15f1, 2020.1.0b10, 2020.2.0a13
Could not test with: 2018.4 because some Scripts are failing to load resulting in only partially functioning project

Devices tested IL2CPP:
Reproducible with:
VLNQA00310 iPad Pro 12.9 (iOS 13.4.1)
VLNQA00204 iPhone 5C (iOS 10.3.3)
VLNQA00160 iPhone 6S iOS 13.3.1
Not reproducible with:
VLNQA00042, Lge LG G3 (LG-D855), Android 5.0, CPU: Snapdragon 801 MSM8974AC, GPU: Adreno (TM) 330
VLNQA00096, Samsung Galaxy S8 (SM-G950F), Android 8.0.0, CPU: Exynos 9 Octa 8895, GPU: Mali-G71
VLNQA00229, Oneplus OnePlus6T (ONEPLUS A6013), Android 9, CPU: Snapdragon 845 SDM845, GPU: Adreno (TM) 630
VLNQA00220, Samsung Galaxy Note9 (SM-N960F), Android 8.1.0, CPU: Exynos 9 Series 9810, GPU: Mali-G72
VLNQA00123, Google Pixel 2 XL (Pixel 2 XL), Android R, CPU: Snapdragon 835 MSM8998, GPU: Adreno (TM) 540
VLNQA00024, Xiaomi Mi 5 (MI 5), Android 7.0, CPU: Snapdragon 820 MSM8996, GPU: Adreno (TM) 530
VLNQA00012, Samsung Galaxy S6 (SM-G920F), Android 7.0, CPU: Exynos 7 Octa 7420, GPU: Mali-T760
VLNQA00122, Samsung Galaxy S9 (SM-G960F), Android 9, CPU: Exynos 9 Series 9810, GPU: Mali-G72
VLNQA00125, Google Pixel 2 (Pixel 2), Android 8.1.0, CPU: Snapdragon 835 MSM8998, GPU: Adreno (TM) 540
VLNQA00321, Xiaomi MI 9 (MI 9), Android 9, CPU: Snapdragon 855 SM8150, GPU: Adreno (TM) 640