Inputted UTC datetime reconvert to UTC datetime as localtime in Datepicker with useUtc=true

[ktanakaj]

Bug description:

Inputted UTC datetime reconvert to UTC datetime as localtime in Datepicker with useUtc=true.

Example, there are following input element and browser timezone is JST (UTC+9). I input text that "2022-02-01 00:00:00" (Not Datepicker's calender). Text box show "2022-01-31 15:00:00".
(I tried many times, sometimes converted but sometimes not converted.)

<input type="text" name="startAt" [(ngModel)]="startAt" bsDatepicker [bsConfig]="{useUtc: true, dateInputFormat: 'YYYY-MM-DD HH:mm:ss'}">

Versions of ngx-bootstrap, Angular, and Bootstrap:

ngx-bootstrap: 8.0.0
Angular: 13.2.1
Bootstrap: 4.6.0
Build system: Angular CLI
Google Chrome; 98.0.4758.82

Expected behavior:

When useUtc=true, inputted datetime is not reconverted.
(I think Datepicker should use default timezone when inputted format has not timezone. But "the default timezone" is not browser timezone. It is UTC in useUtc=true.)