Most likely phase 2 mismatch somewhere. I would follow below sk:
https://supportcenter.checkpoint.com/supportcenter/portal?eventSubmit_doGoviewsolutiondetails=&solut...
Also, on top of that, make sure below 3 settings are set to FALSE in Guidbedit:
ike_enable_supernet
ike_p2_enable_supernet_from_R80.20
ike_use_largest_possible_subnets
I recall even if really old versions of CP, this was an issue where CP always tried to present larger subnet than intended, so say if Cisco is expecting, for example, /28 subnet, CP would have tried to send something bigger, for example/24.
Anyway, had not seen much of that since R80 came out initially, but I would still verify those values.