Dropdown opens but then immediately closes

[dman777]

Description

Polymer 3 paper-dropdown-menu or paper-listbox dropdown closes before a selection is made

Expected outcome

dropdown stays open until a item is clicked on

Actual outcome

the dropdown opens but then closes immediately not giving the user time to select

Live Demo

Please see gif

Browsers Affected

• [ X] Chrome
• [ ] Firefox
• [ ] Safari 9
• [ ] Safari 8
• [ ] Safari 7
• [ ] Edge
• [ ] IE 11
• [ ] IE 10

Both paper-dropdown-menu and paper-listbox are 3.0.1 Chrome 76.0.3809.132 (Official Build) (64-bit)

                <paper-dropdown-menu
                  no-animations
                  id="bedrooms"
                  label="Bedrooms"
                  name="bedrooms">
                  <paper-listbox
                    slot="dropdown-content"
                    class="dropdown-content bedrooms"
                    selected="0">
                    <paper-item>1 bedroom</paper-item>
                    <paper-item>2 bedrooms</paper-item>
                    <paper-item>3 bedrooms</paper-item>
                    <paper-item>4 bedrooms</paper-item>
                    <paper-item>5 bedrooms</paper-item>
                    <paper-item>6 bedrooms</paper-item>
                    <paper-item>7 bedrooms</paper-item>
                    <paper-item>8 bedrooms</paper-item>
                    <paper-item>9 bedrooms</paper-item>
                    <paper-item>10 bedrooms</paper-item>
                  </paper-listbox>
                </paper-dropdown-menu>

[dman777]

Closing this as upgrading to 3.1.0 fixes the issue.