The reagents that you've had for 3 years and stored in your garage have probably gone bad. They don't last forever and storing them in an unheated and unairconditioned space will make them go bad faster. Please store your testing supplies inside and they will last longer.
The HTH kit doesn't seem that reliable as you posted results are inconsistent with you fresh, new and reliable FAS-DPD results.
The only thing you needed from the kit you ordered was the PH and TA. The kit you ordered doesn't have CH which may not be too bad because it isn't as important for vinyl pools like yours. You won't need the FC OTO test from the kit you ordered and you can rely on the FAS-DPD test.
So, that leaves CYA. I don't know how long those reagents last. It might be bad, too. Even if your CYA reagent is good, you may be getting inaccurate results because of the residue. The CYA test needs accurate lighting and the You can order the whole Without an accurate read of CYA you have no idea on how to chlorine your pool. CYA testing kit with a clean vial here: TFTestkits.net
Here is a comparison of the recommended test kits: Pool School - Test Kits Compared
Essentially, you could have had a great kit with everything you need for two seasons for the price of the HTH kit + the price of the kit you ordered from Amazon + a handful of more dollars.
The great thing about getting the TF-100 is that when it is time to start with fresh reagents, you can order a refill kit that costs much less.
The HTH kit doesn't seem that reliable as you posted results are inconsistent with you fresh, new and reliable FAS-DPD results.
The only thing you needed from the kit you ordered was the PH and TA. The kit you ordered doesn't have CH which may not be too bad because it isn't as important for vinyl pools like yours. You won't need the FC OTO test from the kit you ordered and you can rely on the FAS-DPD test.
So, that leaves CYA. I don't know how long those reagents last. It might be bad, too. Even if your CYA reagent is good, you may be getting inaccurate results because of the residue. The CYA test needs accurate lighting and the You can order the whole Without an accurate read of CYA you have no idea on how to chlorine your pool. CYA testing kit with a clean vial here: TFTestkits.net
Here is a comparison of the recommended test kits: Pool School - Test Kits Compared
Essentially, you could have had a great kit with everything you need for two seasons for the price of the HTH kit + the price of the kit you ordered from Amazon + a handful of more dollars.
The great thing about getting the TF-100 is that when it is time to start with fresh reagents, you can order a refill kit that costs much less.