Weirdness when trying to send commands to a Samsung TV

I'm trying to set up my Raspberry Pi as a multi-remote sort of thing, 
which works just fine for 3 other devices I have (LED strip, stereo 
tower and HDMI input switcher). However, I cannot seem to get it working 
for my Samsung TV (model LT22C300).

In order to build the .conf file, I used a separate Pi (let's call it Pi 
B) hooked up to a breadboard with both an IR LED and receiver on it, 
then ran irrecord to get the codes. When I change lirc_options.conf to 
make it act as a sender instead of receiver, my TV responds all fine and 
dandy. Then, when I copy this *exact* config file to Pi A, the TV 
doesn't respond *at all*. Pi B's receiver picks up on the signal just 
fine, and irw properly shows the button name as it's called in the .conf 
file. The IR receiver is also coupled with a regular green LED, which is 
brightly illuminated when I'm trying to send from Pi A from a couple 
meters away. I used the exact same procedure for the other 3 remotes and 
all controlled devices work properly when sending from Pi A.

The IR LED is combined with a transistor on both Pis and I can easily 
get a working range of 5+ meters on them. The TV is barely a meter away 
from the "production" Pi anyways.

Some system specs:
PI A
OS: OSMC (a distro tailored to mediacenter stuff based on Debian, 
currently Stretch)
Kernel: 4.14.34-4
lircd version: 0.9.0

PI B
OS: Debian Buster
Kernel: 4.19.75+
lircd version: 0.10.1

I checked the release notes for the versions after 0.9.0 and I didn't 
find anything that might be relevant. Also, with OSMC lircd is tightly 
coupled to the rest so I can't easily upgrade to lircd 0.10.1, or even 
Buster for that matter. I even tried using raw codes instead of just hex 
masks but that didn't make a difference either.

Any ideas why the TV doesn't respond when sending from Pi A?

~Sahbi