For completeness, I removed all of my Schwab-related users and accounts and recreated them per these instructions (Charles Schwab Bank, N.A., is the second set under that heading). I still observed the same result (with or without brokerId="SCHWAB.COM").

Apologies for the cross post, but I wanted this to show up as an error on the institution page. I am currently getting a 403 error when attempting to download transactions. Here is my GnuCash log:

AqBanking v6.2.2.0stable
Sending jobs to the bank(s)
Sorting commands by account
Sorting commands by account
Sorting commands by provider
Send commands to providers
Send commands to provider "aqofxconnect"
Locking customer "1"
Sending request...
Connecting to server...
Resolving hostname "ofx.schwab.com" ...
IP address is "XXX.XXX.XXX.XXX"
Connecting to "ofx.schwab.com"
Connected to "ofx.schwab.com"
Using GnuTLS default ciphers.
TLS: SSL-Ciphers negotiated: TLS1.3:ECDHE-RSA-AES-256-GCM:AEAD
Connected.
Sending message...
Message sent.
Waiting for response...
Receiving response...
HTTP-Status: 403 (Forbidden)
Unlocking customer "1"

My setup worked back in late February, 2020.

Has anyone verified whether the proscribed OFX settings still work? I am currently unable to retrieve balances or transactions. The last time I tried this was late February, 2020, and it worked then. Here is my GnuCash log:

AqBanking v6.2.2.0stable
Sending jobs to the bank(s)
Sorting commands by account
Sorting commands by account
Sorting commands by provider
Send commands to providers
Send commands to provider "aqofxconnect"
Locking customer "1"
Sending request...
Connecting to server...
Resolving hostname "ofx.schwab.com" ...
IP address is "XXX.XXX.XXX.XXX"
Connecting to "ofx.schwab.com"
Connected to "ofx.schwab.com"
Using GnuTLS default ciphers.
TLS: SSL-Ciphers negotiated: TLS1.3:ECDHE-RSA-AES-256-GCM:AEAD
Connected.
Sending message...
Message sent.
Waiting for response...
Receiving response...
HTTP-Status: 403 (Forbidden)
Unlocking customer "1"

I removed all of my Schwab-related users and accounts and recreated them per these instructions (Charles Schwab Bank, N.A., is the second set under that heading). Still nada (with or without brokerId="SCHWAB.COM").

Any advice? Any additional diagnostics I can conduct?

I just tried changing my email address and received this error:

Sorry! The page could not be loaded.

Unable to send e-mail.
Please contact the forum administrator with the following error message reported by the SMTP server: "535 Incorrect authentication data "

Is anyone else seeing this?

The entry for Monterey Credit Union needs updating. As of April 2017, the new FI URL is:

https://mb.montereycu.com/OFX/OFXServer.aspx