Stamps.com shipping not giving correct rates

Hello, I am a bit stumped. I’m trying out your plugin, using my stamps.com credentials. I have my test product entered with a weight of 0.213 lbs each, I also put dimensions of 10x8x4 inches. I added 10 items to my cart and am trying to calculate shipping. Origin zip code is 74037 and destination zip code is 74137 to test. I put this info into my stamps.com desktop app and the rates I get are $6.09 for Priority Shipping (First Class isn’t an option because it’s too heavy). The rates that are calculated from the plugin are:
First-Class Mail®: $26.00
Priority Mail®: $57.50
First class mail shouldn’t show up because it’s over 15.9 ounces, but what’s more concerning than that is the (vastly) incorrect calculated shipping rates. I turned on debug and this is the first few sections of output:

Auth response:

stdClass Object
(
[Authenticator] => exp=1469579573&uid=7948457&cty=swsim&ctk=h3oOBZxjDD5Ct5vo0iYoUdEdtJE=&iid=rHcPV3RT8Uau54Q3WHYXSw==&rsid=0&irsid=1&eac=1480459706&eacx=29554687&eac3=0&rrsid=0&raid=0&resellerid=0&pexp=0&pl=&ast=1&ipaddr=216.16.142.227&ace=1469496773&mac=e4eBzdpzA2Bz8vFA5S9SsktE2p8=
[LastLoginTime] => 2016-07-26T00:32:49.26
[ClearCredential] =>
[LoginBannerText] =>
[PasswordExpired] =>
[CodewordsSet] => 1
)

Rates request

Array
(
[Authenticator] => exp=1469579573&uid=7948457&cty=swsim&ctk=h3oOBZxjDD5Ct5vo0iYoUdEdtJE=&iid=rHcPV3RT8Uau54Q3WHYXSw==&rsid=0&irsid=1&eac=1480459706&eacx=29554687&eac3=0&rrsid=0&raid=0&resellerid=0&pexp=0&pl=&ast=1&ipaddr=216.16.142.227&ace=1469496773&mac=e4eBzdpzA2Bz8vFA5S9SsktE2p8=
[Rate] => Array
(
[FromZIPCode] => 74037
[ToZIPCode] => 74137
[WeightLb] => 0
[WeightOz] => 3.41
[PackageType] => Package
[Length] => 10
[Width] => 8
[Height] => 4
[ShipDate] => 2016-07-27
[InsuredValue] => 0
[RectangularShaped] => false
)

)

Rates Response

stdClass Object
(
[Authenticator] => exp=1469579573&uid=7948457&cty=swsim&ctk=OQ9tFHkZjl283t+fiL5stvLxjoo=&iid=rHcPV3RT8Uau54Q3WHYXSw==&rsid=0&irsid=1&eac=1480459706&eacx=29554687&eac3=0&rrsid=0&raid=0&resellerid=0&pexp=0&pl=&ast=1&ipaddr=216.16.142.227&ace=1469496773&mac=zSV7BF9GWyqcNHYir4sOzsllE9c=
[Rates] => stdClass Object
(
[Rate] => Array
(
[0] => stdClass Object
(
[FromZIPCode] => 74037
[ToZIPCode] => 74137
[Amount] => 2.6
[ServiceType] => US-FC
[DeliverDays] => 2
[WeightOz] => 3.41
[PackageType] => Package
[Length] => 10
[Width] => 8
[Height] => 4
[ShipDate] => 2016-07-27
[DeliveryDate] => 2016-07-29
[DimWeighting] => N
[AddOns] => stdClass Object
(
[AddOnV7] => Array
(
[0] => stdClass Object
(
[AddOnType] => US-A-INS
[ProhibitedWithAnyOf] => stdClass Object
(
[AddOnTypeV7] => Array
(
[0] => US-A-REG
[1] => US-A-CM
[2] => US-A-COD
[3] => SC-A-INS
)

)

[MissingData] => InsuredValue
)

There’s obviously more but it’s very long, I figured it would be best to wait and see if you need the full body of the debug before flooding the page. Let me know what you think, thanks!

https://wordpress.org/plugins/woo-stamps-com-shipping-method/