OK that’s great, you no longer get white screen when you trigger the cron job manually. Normally the cron job triggers on its own, I only suggested that you trigger it manually to make sure.
You are still experiencing withdrawals which stay in a pending state, even after they are confirmed by an admin AND by the user. And you are using a connection to a full node wallet, which is unlocked. This is very unusual.
First, have you tried entering a new withdrawal again, after upgrading? If your problem was caused by too little memory, then you should repeat the test.
Also, could you please let me know the following?:
1. Which wallet are you using?
2. Normally withdrawals start off with 3 retries. When you trigger the cron job, does the number of remaining retries decrease? Normally when the number gets to 0, you will get an email with an error message.