Welcome!
X-series can be pretty picky, especially as you already said within the first few weeks of installation, unfortunately part of it comes down to just learning the correct position
But, there are some things you can do to make it easier on yourself
If you don’t already have one, a booster board is basically magic, and should help a lot
The usual orientation that works is to have the chip perpendicularly crossing the relevant antenna, there’s some picture examples in this post:
That’s a good place to start, but you’ll likely need to do a little fine tuning. To help you with that, you may try:
hf tune
And / or
hf 14a reader -@
These commands give you continuous feedback to help you find the “sweet spot”, with the former you look for the lowest voltage values, and with the second you look for the most consistent reads