It likely the AT!USBCOMP needs to be something specific. Generally that's MBIM for 4G sierras... but I don't have EM7565 to say specifically.
You can put the LTE into serial mode.
/interface/lte/settings/set mode=serial
And then reboot, maybe some ports shows up... With at least one AT channel, you can use AT commands on the modem.
So assuming you get a port(s) after reboot and mode=serial, you can use
/system/serial-terminal usbX channel=Y
Adjusting as port/channel as needed.
I'd focus on the output of:
AT!CUSTOM?
AT!USBCOMP?
AT!USBCOMP=?
But I suspect the USBCOMP needs to be something specific for it to show up. AT!USBCOMP=? should describe the format, AT!USBCOMP? will show what's currently set, and AT!USBCOMP=xxxxxx is how you'd set it.
I don't have the AT manual for the 7565, but it is some bitfields in USBCOMP settings...so can't tell you off-hand what's right on you modem. But you'll want to set it to MBIM, just don't know specific magic string for your particular modem.
You may have to open a ticket with mikrotik about this, since sometimes it's hard to guess the needed modem settings (or there is a bug/etc that prevents it from working). But pretty sure the USBCOMP is what's needs to be right. And the various output above give Mikrotik some details to work with if you need a ticket for this.
You'll need to put the LTE modem back to "auto" after your done with the serial port to see if any changes work:
/interface/lte/settings/set mode=auto