To reproduce:

1. Download and open attached "WebRequestWWW_APItest564p2.zip" project.
2. Build and run on a one of the devices which reproduces the issue.
3. Make sure your current scene is WebRequestGet.
4. Press WebRequest button.

Expected Result: Following text appears on the screen: startingWebRequest Content length is 5 Content is test!
Actual result: Following text appears on the screen: Unable to complete SSL connection.

Reproduced in: 2018.1.0a7, 2017.3.0f1, 2017.2.1f1, 2017.1.2p4.

Devices under test:

Reproduces with:
Asus K011*, OS:4.4.2, CPU:x86, GPU:Intel/BayTrail, Build:asus/WW_K011/K011:4.4.2/KOT49H/WW_user_3.1.23.191_20160107:user/release-keys
Samsung GT I8200N*, OS:4.2.2, CPU:armeabi-v7a, GPU:Vivante GC1000, Build:samsung/goldenve3gxx/goldenve3g:4.2.2/JDQ39/I8200NXXUANI2:user/release-keys

Did not reproduce with:
Asus P01Z*, OS:5.0.2, CPU:x86, GPU:Mali-450 MP, Build:asus/WW_P01Z/P01Z:5.0.2/LRX22G/WW_ZenPad-12.26.4.57-20160419:user/release-keys
Google Pixel*, OS:8.0.0, CPU:arm64-v8a, GPU:Adreno (TM) 530, Build:google/sailfish/sailfish:8.0.0/OPR3.170623.008/4294783:user/release-keys
Nvidia SHIELD Tablet*, OS:6.0.1, CPU:armeabi-v7a, GPU:NVIDIA Tegra, Build:nvidia/wx_na_wf/shieldtablet:6.0.1/MRA58K/49349_766.5399:user/release-keys
Xiaomi Mi 4i*, OS:5.0.2, CPU:arm64-v8a, GPU:Adreno (TM) 405, Build:Xiaomi/ferrari/ferrari:5.0.2/LRX22G/V8.5.3.0.LXIMIED:user/release-keys

Notes: The same happens when running the WebRequestDownloadHandler scene. WebRequestDownloadTextureHandler also does not return results on these two devices. The reproducible devices both run Android 4 OS, all other tested devices run 5 or newer OS.