DeBug-Log file created on every order for Malformed value for session-based shipping

lat9:

What shipping modules are enabled?

Just Advanced Shipper on my site.

twitchtoo:

Debug Log:
[18-May-2021 02:23:21 America/Chicago] PHP Notice: Malformed value for session-based shipping module; customer will need to re-select: false in includes/classes/order.php on line 327

Suggested fix at least for this variant of the issue:

https://github.com/zencart/zencart/pull/4829

Update: Unfortunately, I still received another debug log after I used the fix mentioned above. This log is triggered by the table.php. I'm using the table.php based on version $Id: DrByte 2020 Sep 29 Modified in v1.5.7a (from zc 1.57d). This issue is intermitted. Typically I will receive one log once per month or so.

[12-Jul-2022 11:12:32 America/New_York] PHP Notice: Malformed value for session-based shipping module; customer will need to re-select: {"id":"","title":"Table Rate (Best Way)","cost":76.9899999999999948840923025272786617279052734375} in /public_html/includes/classes/order.php on line 324

Line 324 is the following:
trigger_error('Malformed value for session-based shipping module; customer will need to re-select: ' . json_encode($_SESSION['shipping']), E_USER_NOTICE);

My site (v1.57d) doesn't offer free shipping option.

The shipping methods my site offers are the following:

fedexwebservices
storepickup
table
usps

Here are the payment methods:
paypal express
paypal payment pro

I'm currently using OPC plug-in, but I still received this intermittent issue before I installed OPC.

Update. I just noticed that zc 1.5.8 Alpha was just released. I uploaded the table.php file from it to my site (direct link). It seems working without log files, and I will report if this issue happens again.

One more update. Today I received the same error again. So the table.php from zc 1.5.8 Alpha does not fix this intermittent issue.

I'm guessing this is a dead issue, but I'll report anyway.

Just upgraded from 156 to 157d and am getting this error.

It occurs regularly and is triggered by two possibilities.

BTW my options are store pickup and zipship.

If the customer changes the address to successfully make zipship an option then I get the error.

Or if I select store pickup, then press continue, the error is also then triggered.