You’re probably dealing with a kernel or I2C-HID regression rather than a dead touchpad. The fact that it worked perfectly for ~2 weeks and your USB mouse still works is a strong indicator that the hardware itself is likely fine.
Acer Aspire 5 laptops have had repeated Linux touchpad issues across multiple Ubuntu/kernel releases, especially with ELAN and Synaptics I2C devices under Wayland. In a lot of cases the touchpad suddenly disappears after a kernel update or fails to initialize during boot.
Since Ubuntu 26.04, testing a GNOME Xorg session is no longer really an option because Ubuntu dropped the GNOME X11 session starting with 25.10/26.04.
At this point I’d focus more on whether the kernel is still detecting the touchpad at all rather than trying to switch display servers.
First thing I would check is whether the system still even sees the touchpad:
libinput list-devices
and:
sudo dmesg | grep -iE 'touchpad|i2c|hid|elan|synaptics`
If nothing related to the touchpad appears there, the kernel is failing to initialize the device.
Also check the obvious Acer-specific toggle:
Fn + F7
A surprising number of Aspire owners accidentally disable the touchpad that way and Linux gives zero useful feedback when it happens.
If the device disappeared there after an update, this is very likely a kernel or I2C-HID regression rather than a Wayland issue.
Another important thing:
check whether Ubuntu installed a newer kernel shortly before the problem started.
Run:
uname -r
If the issue started after a kernel update, boot an older kernel from:
GRUB → Advanced options for Ubuntu
If the touchpad works again on an older kernel, then you’ve confirmed this is a regression and not a hardware fault.
I would not reinstall the OS yet. Reverting the entire distro back to 24.04 without confirming the actual cause is overkill and may not even solve it permanently if the same kernel branch gets installed later.
Also worth checking BIOS settings. Some Acer models expose touchpad modes like:
Linux sometimes behaves much better in the compatibility/PS2 mode.
At this point I would troubleshoot in this order:
1. Fn+F7 toggle
2. Verify detection with libinput/dmesg
3. Test X11 instead of Wayland
4. Boot older kernel from GRUB
5. Check BIOS touchpad mode
6. Only consider reinstall/downgrade after confirming it is not kernel-related
Please check if similar issues have already been reported and resolved.