We had this in another thread here recently.
The problem is that the new default bootloader for new Tumbleweed / Slowroll installation is now grub-bls which wants to store all kernels and all initrds on the EFI System Partition (/boot/efi). That of course means that this ESP needs to be large enough to hold all those files.
I consider that a totally hare-brained idea, and I have no idea why this irresponsible decision was made; it’s an accident waiting to happen for all users who have been using the older grub2-efi for many years, when each Linux distro would consume just something around 5 MiB on the ESP.
grub2-efi is still there; it’s just not the default anymore. Install the package, change the bootloader configuration to use it, reinstall the bootloader.
IIRC there are instructions for this in that other thread.
Edit: The other thread: Install Dual Boot with Existing small EFI Partition