cloned shipping module does not appear in checkout

I cloned the ground shipping module and called it FedEx Three Day after reading these and many other threads about cloning shipping modules:

https://www.zen-cart.com/tutorials/index.php?article=189

I installed my cloned module through the admin interface. Unfortunately, when I go to the checkout page, it does not appear as one of the shipping options. If I uninstall ground shipping, my cloned module does appear. I have different sort orders for each module as well.

I have been careful to replace all constants. Nothing has the word 'GROUND' or 'ground' in it.

Is there something special about cloning Ground shipping that makes it a bad idea?

Update: Our installation is Zen Cart 1.3.7. I am getting strange behavior. The cloned shipping module does appear, but only if I disable one of the other shipping modules. Right now I have

Two flat rate clones and one overnight shipping module, leaving me with:

Flat
FlatTwo
FlatThree
Overnight

Only two of the flats will appear at a time in addition to the overnight. Switching sort orders will swap out one for the other, but no three will co-exist at once. I give different sort orders to all.

If I install ground shipping, all three flats appear plus the overnight, leaving:

Flat
FlatTwo
FlatThree
Ground
Overnight

But I don't want Ground, and I'm not sure why installing ground enables all three Flats?

What is the filename of the FlatTwo shipping module, class name and what is the status constant?

What is the filename of the FlatThree shipping module, class name and what is the status constant?

What is the filename of the Ground shipping module, class name and what is the status constant?

Example: Flat Rate uses:
filename: flat.php
class flat
status constant: MODULE_SHIPPING_FLAT_STATUS

I have been trying a few things in an attempt to make this all work. I now have four clones of the same flat module. They are named as such:

filename: flat.php (sort order 50)
classname: flat
statusconst: MODULE_SHIPPING_FLAT_STATUS

filename: flatground.php (clone of flat, sort order 10)
classname: flatground
statusconst: MODULE_SHIPPING_FLATGROUND_STATUS

filename: threeday.php (clone of flat, sort order 20)
classname: threeday
statusconst: MODULE_SHIPPING_THREEDAY_STATUS

filename: flatsecday.php (clone of flat, sort order 30)
classname: flatsecday
statusconst: MODULE_SHIPPING_FLATSECDAY_STATUS

**filename: **flatovernight.php (clone of flat, sort order 40)
**classname: **flatovernight
statusconst: MODULE_SHIPPING_FLATOVERNIGHT_STATUS

I have verified all the constants have been replaced appropriately in all four files. No matter what combination of sort orders I try and no matter which single one of these five I install, only three remain.

My goal is to get four flat shipping rates going.

Solved! I took over this version of the store from another developer who used javascript to hide the second shipping option in the tpl_checking_shipping_default.php file.

My cloned flat rate shipping options were fine.

Thanks for those who offered their help.

Please don't take this as a scolding....
It's not specifically in the Posting Tips, but a simple starting statement of "I recently took over this site" would have led to different answers and, possibly, a quicker fix.

Not just you, but many others, leave out details that can help us help you.

Glad you got it going.:clap:
Isn't it great to know it wasn't something you did?:flex:

Glad you found the solution as all of those are working for me just fine ... :cool: