The problem comes from udev and its way of mounting dev points.
It is possible to create rules to obtain a static point according to the manufacturer's name
wiki.archlinux.org/title/Udev#Setting_static_device_names

A tutorial made by Indi to create the rules file
www.indilib.org/support/tutorials/157-pe...al-port-mapping.html

It would be interesting to know the identifier of your GPS and the USB/RJ cable of your mount. And check if they are in the rules /lib/udev/rules.d/25-gpsd-usb.rules and /lib/udev/rules.d/69-libftdi.rules
To find them, use the following command as noted in the tutorial

"To find out the serial ID, run the following command against the device node. For example, the find the serial id of the device connected to /dev/ttyUSB0:"

udevadm info -a -n /dev/ttyUSB0 | grep '{serial}' | head -n1

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