Installed Win 10 & Maté on added internal 500GB SSD in eMMC laptop. GRUB selected Maté, or Win on SSD, or Win on eMMC, i.e. OS selection working as expected.
Laptop failed, replaced under warrantee.
Installed same SSD on replacement laptop.
No GRUB menu.
Win boot manager recognises and launches Win on SSD and Win on eMMC but does not see Maté, marks it as empty space on SSD. Win on SSD runs normally, and all previous Win data is available, so I assume that Maté also is undamaged and problem is loss of GRUB menu because SSD is now on a different computer.
How do I get back the GRUB menu?