Can't save values for particular keys of Map

[holem]

Prerequisites

• I have written a descriptive issue title
• I have searched existing issues to ensure the bug has not already been reported

Mongoose version

8.9.0

Node.js version

22.9

MongoDB server version

8.0.1

Typescript version (if applicable)

No response

Description

For the field of Map type - if key in format "[number]" (number in square brackets) or "[number" (number preceded by square bracket) then it's not saving.

Steps to Reproduce

const ThingSchema = new mongoose.Schema({
  nums: { type: Map, of: [{ type: Number }], default: new Map() },
});
const Thing = mongoose.model("Thing", ThingSchema);

const thing = new Thing();

thing.nums.set("[0]", [1]);
thing.nums.set("[111]", [2]);
thing.nums.set("[,]", [3]);
thing.nums.set("[!]", [4]);
thing.nums.set("[111-]", [5]);
thing.nums.set("[-111]", [6]);
thing.nums.set("111]", [7]);
thing.nums.set("[111", [8]);
thing.nums.set("111", [9]);
thing.nums.set("0", [10]);

console.log("thing.nums", user.nums);
await thing.save();

const thing2 = await Thing.findById(thing._id.toString());
console.log("thing2.nums", thing2.nums);

output:

thing.nums Map(10) {
  '[0]' => [ 1 ],
  '[111]' => [ 2 ],
  '[,]' => [ 3 ],
  '[!]' => [ 4 ],
  '[111-]' => [ 5 ],
  '[-111]' => [ 6 ],
  '111]' => [ 7 ],
  '[111' => [ 8 ],
  '111' => [ 9 ],
  '0' => [ 10 ]
}
thing2.nums Map(7) {
  '0' => [ 10 ],
  '111' => [ 9 ],
  '111]' => [ 7 ],
  '[!]' => [ 4 ],
  '[,]' => [ 3 ],
  '[-111]' => [ 6 ],
  '[111-]' => [ 5 ]
}

Expected Behavior

All values ​​for all string keys are preserved.