Deadlocks on High Frequency Updates

Using SQL Server 2022, I'm stress testing an UPDATE statement. I'm using a python script to send parallel requests to the database. The problem is that, as soon as the number of parallel requests exceed max_workers_count, 576 in my case, I get multiple errors of the form:

('40001', '[40001] [Microsoft][ODBC Driver 17 for SQL Server][SQL Server]Transaction (Process ID 448) was deadlocked on lock | thread resources with another process and has been chosen as the deadlock victim. Rerun the transaction. (1205) (SQLExecDirectW)')

I wasn't able to reproduce the error with less requests than max_workers_count.

The UPDATE request is the following:

UPDATE dbo.UsersAnswer SET UsersSelectionType = ? WHERE For_Question = ? AND For_Quiz = ? AND FK_Answer = ?;

Note that, I've tried with and without (UPDLOCK, ROWLOCK) and (UPDLOCK), but it doesn't change the outcome. Also, the updates are done for the same primary key. 

Finally, the UsersAnswer table is created as follows:

CREATE TABLE [dbo].[UsersAnswer](
    [For_Question] [smallint] NOT NULL,
    [For_Quiz] [uniqueidentifier] NOT NULL,
    [FK_Answer] [int] NOT NULL,
    [UsersSelectionType] [tinyint] NOT NULL,
 CONSTRAINT [PK_UsersAnswer] PRIMARY KEY CLUSTERED 
(
    [For_Question] ASC,
    [For_Quiz] ASC,
    [FK_Answer] ASC
)WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON, OPTIMIZE_FOR_SEQUENTIAL_KEY = OFF) ON [PRIMARY]
) ON [PRIMARY]
GO

ALTER TABLE [dbo].[UsersAnswer]  WITH CHECK ADD  CONSTRAINT [FK_UsersAnswer_Answer_FK_Answer] FOREIGN KEY([FK_Answer])
REFERENCES [dbo].[Answer] ([PK_Answer])
GO

ALTER TABLE [dbo].[UsersAnswer] CHECK CONSTRAINT [FK_UsersAnswer_Answer_FK_Answer]
GO

ALTER TABLE [dbo].[UsersAnswer]  WITH CHECK ADD  CONSTRAINT [FK_UsersAnswer_QQ_For_Question_For_Quiz] FOREIGN KEY([For_Question], [For_Quiz])
REFERENCES [dbo].[QQ] ([FK_Question], [FK_Quiz])
ON DELETE CASCADE
GO

ALTER TABLE [dbo].[UsersAnswer] CHECK CONSTRAINT [FK_UsersAnswer_QQ_For_Question_For_Quiz]
GO

Do you have any idea on what could cause the deadlock? The deadlock graph is huge, you can find it https://drive.google.com/file/d/1cs_-QULtF0yBsqOIzab56l9oYxKypbUV/view?usp=sharing.

Thanks for your insights on this.