First Class Domestic, not shown

[split63]

PHP 5.6
Zen: v1.57c
USPS module: USPS Version Date: 2021-05-05 K11a

No problems shipping USPS Priority. For the first time, we enabled "1st-Class Pkgs - Retail"

For a domestic package weighing <13 oz, no first class shipping line is displayed, only priority.
We have the size minimums set to 9" x 4" x 3" (As this is our standard shipping box)

I turned on the USPS module logs. No errors inside, but the only mention of "first class" is

Enable USPS First-Class filter for US shipping: False

What should I be looking for?
I checked the USPS.php file, it has no code modifications.

[swguy]

You want Enable USPS First-Class filter for US shipping = True.
Also you should be running PHP 7.4 - PHP 5.6 is way out of date.

[lat9]

PHP 5.6
Zen: v1.57c
USPS module: USPS Version Date: 2021-05-05 K11a

No problems shipping USPS Priority. For the first time, we enabled "1st-Class Pkgs - Retail"

For a domestic package weighing <13 oz, no first class shipping line is displayed, only priority.
We have the size minimums set to 9" x 4" x 3" (As this is our standard shipping box)

I turned on the USPS module logs. No errors inside, but the only mention of "first class" is

Enable USPS First-Class filter for US shipping: False

What should I be looking for?
I checked the USPS.php file, it has no code modifications.

For 1st Class postage, the USPS enforced minimums are the default values set: 8.625" x 5.375" x 1.625". Your minimums are higher, so USPS won't return the 1st-Class rates.

You can enable the USPS debug to review the quotes returned.

[split63]

You want Enable USPS First-Class filter for US shipping = True.

Setting this False or True has no affect

[split63]

For 1st Class postage, the USPS enforced minimums are the default values set: 8.625" x 5.375" x 1.625". Your minimums are higher, so USPS won't return the 1st-Class rates.
You can enable the USPS debug to review the quotes returned.

I changed the minimums to the defaults, I left the minimums blank, neither change had any affect.
Logs show no errors, no issues

[split63]

Instead of "1st-Class Pkgs - Retail", I enabled "1st-Class Pkgs - Comm" and it works.
Seems like a bug

[lat9]

I changed the minimums to the defaults, I left the minimums blank, neither change had any affect.
Logs show no errors, no issues

The log's not going to show errors, just which shipping options it returned.