Month is not localized to EN after switching language in Thymeleaf/Spring Boot webapp

I am writing a spring boot application using Thymeleaf as template engine.

My web app has English and Ukrainian locales.

The issue is that Month of dates is ALWAYS localized to UA (Ukrainian) locale: i.e. 11-травня-2020

If I change locale to English using language picker the date is still the same (11-травня-2020), provided that other parts are translated.

If I try to use new java.util.Locale('en', 'EN') then 11-May-2020 date is displayed (as expected).

HTML part where I use my dates in the table:

<table class="table table-bordered table-striped ">
        <thead class="thead-dark">
        <tr>
          ...

            <th></th>
        </tr>
        </thead>

        <tbody>
        <tr th:each="tempReport : ${page}">
            
           ...

            <td th:text="${#temporals.format(T(java.time.LocalDate).of(#dates.year(tempReport.reportDate),
                #dates.month(tempReport.reportDate), #dates.day(tempReport.reportDate)),
                'dd-MMMM-yyyy', new java.util.Locale('uk', 'UA'))}"
             ></td>

        </tr>
        </tbody>
</table>

My locale configuration:

@Configuration
public class Localization implements WebMvcConfigurer {

    @Bean
    public LocaleResolver localeResolver() {
        SessionLocaleResolver resolver = new SessionLocaleResolver();
        resolver.setDefaultLocale(Locale.ENGLISH);
        return resolver;
    }

    @Bean
    public LocaleChangeInterceptor localeChangeInterceptor() {
        LocaleChangeInterceptor interceptor = new LocaleChangeInterceptor();
        interceptor.setParamName("lang");
        return interceptor;
    }

    @Override
    public void addInterceptors(InterceptorRegistry registry) {
        registry.addInterceptor(localeChangeInterceptor());
    }
}

My Language picker:

<div class="collapse navbar-collapse" id="navbarResponsive">
            <ul class="navbar-nav ml-auto">

                <li class="nav-item dropdown active ml-5">
                    <a class="nav-link dropdown-toggle" href="#" id="navbarDropdownMenuLink" role="button"
                       data-toggle="dropdown" aria-haspopup="true" aria-expanded="false"
                       th:text="${#strings.toUpperCase(#locale)}">
                    </a>
                    <div class="dropdown-menu" aria-labelledby="navbarDropdownMenuLink">
                        <a class="dropdown-item" th:href="@{?lang=en}" th:text="#{navigation.eng}"></a>
                        <a class="dropdown-item" th:href="@{?lang=ua}" th:text="#{navigation.ua}"></a>
                    </div>
                </li>

            </ul>
        </div>

Any help to resolve the issue will be appreciated!