Depends on whuch spec you mean. Older versions of safari (anf chrome) were following the original proposed standard (rfc 6265), which said invalid values should

Depends on whuch spec you mean. Older versions of safari (anf chrome) were following the original proposed standard (rfc 6265), which said invalid values should be treated as strict. Later versions of Chrome are following a later internet-draft (rfc 6265bis, which I think was proposed by google), that introduced SameSite=none, and changed the behavior for unknown values to be the same as none.