Non-working sites: https://chat.deepseek.com/sign_in

[mpetruc]

Exact login URL and the URL of your entry or entries.: https://chat.deepseek.com/sign_in
Dump of console output from the page (Firefox: Tools -> Browser Tools -> Web Developer Tools / Chromium-based: Tools -> Developer -> Javascript Console). Do this only if there's KeePassXC-Browser related output.
Have you tried Username-Only Detection, choosing Custom Fields etc. Yes
Are you using Autofill instead of the manual one. Yes
Does it affect the Username Icon, Autocomplete Menu, Popup Menu?
Version 1.8.0 and later, enable Debug Logging from the settings and inspect the pages's JavaScript console. It should show all input fields detected.

[Debug keepassxc-browser.js:349] KeePassXC-Browser - Login field combinations identified:
global.js:163 Array(1)0: {username: input.ds-input__input, password: input.ds-input__input, passwordInputs: Array(1), totp: null, fields: Array(0)}length: 1[[Prototype]]: Array(0)
global.js:160 [Debug observer-helper.js:217] KeePassXC-Browser - Input fields found:
global.js:163 Array(2)0: input.ds-input__input1: input.ds-input__inputlength: 2[[Prototype]]: Array(0)at: ƒ at()concat: ƒ concat()constructor: ƒ Array()copyWithin: ƒ copyWithin()entries: ƒ entries()every: ƒ every()fill: ƒ fill()filter: ƒ filter()find: ƒ find()findIndex: ƒ findIndex()findLast: ƒ findLast()findLastIndex: ƒ findLastIndex()flat: ƒ flat()flatMap: ƒ flatMap()forEach: ƒ forEach()includes: ƒ includes()indexOf: ƒ indexOf()join: ƒ join()keys: ƒ keys()lastIndexOf: ƒ lastIndexOf()length: 0map: ƒ map()pop: ƒ pop()push: ƒ push()reduce: ƒ reduce()reduceRight: ƒ reduceRight()reverse: ƒ reverse()shift: ƒ shift()slice: ƒ slice()some: ƒ some()sort: ƒ sort()splice: ƒ splice()toLocaleString: ƒ toLocaleString()toReversed: ƒ toReversed()toSorted: ƒ toSorted()toSpliced: ƒ toSpliced()toString: ƒ toString()unshift: ƒ unshift()values: ƒ values()with: ƒ with()Symbol(Symbol.iterator): ƒ values()Symbol(Symbol.unscopables): {at: true, copyWithin: true, entries: true, fill: true, find: true, …}[[Prototype]]: Object
global.js:160 [Debug keepassxc-browser.js:349] KeePassXC-Browser - Login field combinations identified:
global.js:163 Array(1)0: {username: input.ds-input__input, password: input.ds-input__input, passwordInputs: Array(1), totp: null, fields: Array(0)}length: 1[[Prototype]]: Array(0)
global.js:160 [Debug observer-helper.js:217] KeePassXC-Browser - Input fields found:
global.js:163 []length: 0[[Prototype]]: Array(0)

No "Username or password changed! Save it?" pop up appears after submitting the credentials.

[varjolintu]

I had no problems with the site if my entry URL was https://deepseek.com.