If a product is FCC certified, there are some reports available for all to see on the internet.
Look at the output power section for StickNFind:
We have -0.3 – 0.84dBm (0.93mW – 1.21mW).
The NRF 51822 inside the StickNFind is a 4dBm (2.5mW) device. FCC maximum power output tests ignore the antenna, so that’s nowhere near the maximum. I realise these tags need to be low power, but is this why the range is nowhere near as high as expected?
As an aside, they appear to use the piezo buzzer as the antenna, so if yours come apart like one of mine did, expect it to not work. It might also explain the squeezing causing them to work better – it might not be the battery but the spring contacts to the buzzer.