I did LORA 2.4GHz several years ago. It depends on the TX pin out impedance, the antenna input impedance, and PCB layers definition.
Maybe your calculation model was not right. It should be considered as the CPW, and aforesaid, the 2nd layer should be cut.
Use the recommendation always works, and add some special filter for special application.
If you use different antenna, then use different matching components.
And, the RF 50 ohms maybe have +-10% error.
Best,
Tony Liu