How to make <thead> non-scrollable in ionic2?

Hello,

I am using Ionic CLI Version 2.2.2 (which is absolutely sufficient for my app) and do have the problem that I need a <thead> within <table> non-scrollable in vertical direction too. “Too” because my <ion-nav-title> is already vertically non-scrollable.

Googling and testing around with i.e. jqueries, 2 tables instead of <thead> and <tbody> did not work so far. So what would I have to change in the following code to have it working?

<ion-view>
    <ion-nav-title>My title</ion-nav-title>

    <ion-nav-buttons side="primary">
        <a ng-click="showABC()" class="button button-icon icon icon-android-settings"></a>
        <a ng-click="showDEF()" class="button button-icon icon icon-group"></a>
    </ion-nav-buttons>
    
    <ion-nav-buttons side="secondary">
        <a ng-click="reset()" class="button button-icon icon ion-trash-a"></a>
        <a ng-click="showInformation()" class="button button-icon icon icon-information-circled"></a>
    </ion-nav-buttons>

    <ion-content class="game has-footer" padding="false">
        <table>
            <thead>
                <tr>
                    <th rowspan(...)</th>
					(...)
                    <th colspan (...)</th>
					(...)
                    <th ng-if="functionGHI()" colspan="3" class="separator-left"><div class="ellipsis">{{functionIJK()[4]}}</div></th>
                    <th rowspan="2" class="separator-left"><div class="vertical"><div class="vertical__text">SomeText01</div></div></th>
                </tr>
                <tr>
                    <th> (...)</th>
                    <th ng-if="functionLMN()" class="separator-left">Pos.<br>SomeText02</th>
                    <th ng-if="functionOPQ()" class="small"><div class="vertical"><div class="vertical__text">SomeText03</div></div></th>
                    <th ng-if="functionRST()" class="small"><div class="vertical"><div class="vertical__text">SomeText04</div></div></th>
                </tr>
            </thead>
            <tbody>
                <tr ng-repeat="item in functionUVW().methodOPQ" ng-class="{'separator': functionUVW().isSeparator($index)}">
                    <td> (...) </td>
                </tr>
            </tbody>
            <tbody>
                <tr>
                    <td> (...) </td>
                    (...)
 
                </tr>
            </tbody>
        </table>
    </ion-content>

    <ion-footer-bar class="bar bar-balanced">
        <a ng-click="functionXYZ" class="button button-icon icon icon-minus"></a>
        <h1 (...) </h1>
        <a ng-click="function123()" class="button button-icon icon icon-plus"></a>
    </ion-footer-bar>
	
</ion-view>

Thanks in advance.