Position of tooltip is slightly shifted

[kubica]

Bug description:

This issue is similar to #1845. The tooltip arrow is not shown at the middle of the element (see picture).

Same problem for placement="right" etc.

Link to minimally-working plunker that reproduces the issue:

http://plnkr.co/edit/EPGCNPOGN0EAKXUCwAU3?p=preview

Workaround

.bs-tooltip-top .arrow, .bs-tooltip-bottom .arrow {
    margin-left: -2px;
}
.bs-tooltip-left .arrow, .bs-tooltip-right .arrow {
    margin-top: -2px;
}

Version of Angular, ng-bootstrap, and Bootstrap:

Angular: 5.0.2

ng-bootstrap: 1.0.0-beta.8

Bootstrap: 4.0.0-beta.2

[bastienmoulia]

Actually there is in the CSS of the tooltip arrow

left: 50%;

And we can use

left: calc(50% - 2.5px);