When ranking hits, geo distances are grouped into ranges of aroundPrecision size. All hits within the same range are considered equal with respect to the geo ranking parameter. For example, if you set aroundPrecision to 100, any two objects lying in the range [0, 99] from the searched location will be considered equal; same for [100, 199], [200, 299], etc. This will allow items that are relatively close to be ranked the same in the "geo" criterion and let the textual criteria do the tie breaking.
In your current setting, aroundPrecision could be too small a number meaning that unless you move geo to the bottom, everything is effectively getting sorted by how far away it is on a meter by meter basis. In general, we do not advise changing the default ranking formula so it would be preferable to change the aroundPrecision.