My QFX file not uploading since the new update. Anyone else struggling with this problem ?

Thank you for posting your concern here, @userroyalplumbingpe. I know how important it is upload your bank data file to QuickBooks. I've got ways to help yo uresolve this issue.
 

When manually uploading transactions in QuickBooks Online, make sure to review the file format and size. To do this, open and examine the file from your bank. 

You can use the 3 column format or 4 column format. Keep in mind that the maximum file size is 350 KB. If the file is too big, shorten the date range and download transactions in smaller batches.

Here are some screenshots for reference:
 

Once everything is accurate, you can start uploading the transactions. Let me show you how:

1. Go to the Banking menu and select Upload transactions.
2. Press Browse and then click the QFX file you downloaded from your bank and tap Next.
3. In the QuickBooks account ▼  dropdown, choose the account you want to upload the transactions into and then click Next.
4. Follow the onscreen steps and choose Next.
5. Select the transactions you would like to import and click Next.
6. Choose Yes, then tap Let's go.
   
   
   
   

Se this article for the complete steps of getting transactions into the program: Manually upload transactions into QuickBooks Online.

Once you're all set, you might want to check out these resources that can guide you in flawlessly managing your accounts: 
 

• Categorise and match online bank transactions in QuickBooks Online
• Reconcile an account in QuickBooks Online

If you have additional concerns while working in QBO, leave a comment below. I’ll be happy to help you out. Have a wonderful day.

Try opening your QBO account on any private/incognito browser.