Generic type not assignable if extends type with optional field and passed object does not include the optional field

TypeScript Version: 3.9.2

Search Terms:
optional generic "not assignable"

Code

const foo = <V extends { s?: string }>(v: V) => {};

// This works:
foo({ s: "1", v: 2 });

// This doesn't work:
foo({ v: 2 }); // Argument of type '{ v: number; }' is not assignable to parameter of type '{ s?: string | undefined; }'. Object literal may only specify known properties, and 'v' does not exist in type '{ s?: string | undefined; }'.

Compare with

const bar = <V extends { }>(v: V) => {};

// Both work:
bar({ s: "1", v: 2 });
bar({ v: 2 });

Expected behavior:
Both statements in the first snippet should compile.

Actual behavior:
foo({ v: 2 }); doesn't compile for const foo = <V extends { s?: string }>(v: V) => {};

Playground Link:
https://www.typescriptlang.org/play?#code/MYewdgzgLgBAZiEMC8MA8A1GBTAHlbMAEwhgG8YIB+ALkqgCcBLMAcxgF8A+ACgDc6GAJQou5ALAAoKRwDcUhCB4UIdAEQBGNQBoYAmACZOQ+ZMXK9dIxxNSpoSLABGAQwYp0WPAWKkK3fkERZDEyOTtJAHpImAAhECgACxgAdxAGAGsaKVcGC1UYTR1LQ2NTXIt9axMgA

Related Issues:

Possible remotely related... https://github.com/microsoft/TypeScript/issues/13747

Start by running the TypeScript 3.9.2 reproduction in the provided Playground link and compare the two generic calls. Trace the type-checking behavior for excess properties on a generic constraint with an optional field. Done means both calls in the first snippet compile without changing the behavior shown for the second snippet.