Quote from ISW's Assesment from June 18th
Ukrainian forces may be temporarily pausing counteroffensive operations to reevaluate their tactics for future operations. Head of the Estonian Defense Forces Intelligence Center Colonel Margo Grosberg stated on June 16 that he assesses "we won't see an offensive over the next seven days.”[7]The Wall Street Journal similarly reported on June 17 that Ukrainian forces “have mostly paused their advances in recent days” as Ukrainian command reexamines tactics.[8] These reports are consistent with ISW’s recent observations of the scale and approach of localized Ukrainian counterattacks in southern and eastern Ukraine.[9] ISW has previously noted that Ukraine has not yet committed the majority of its available forces to counteroffensive operations and has not yet launched its main effort.[10] Operational pauses are a common feature of major offensive undertakings, and this pause does not signify the end of Ukraine’s counteroffensive.

Liveuamap shows some attacks on behalf of AFU, so they haven't halted, they curbed the volume down (as Wall Street Journal was quoted).
NATO observers clearly see that things aren't going well, probably they go very badly. But they also note rightly that most of the prepared brigades aren't doing anything.
Anyway Ukraine tried to form armoured columns, ended with heavy losses. Then tried infantry on foot, ended with heavy losses. They did some decent maneuvering and flanking south of Velike Novosilka, but they suffered high losses.
They really need air cover and air defense. And even then the go still might remain very bumpy.

I was musing what'll happen on the long run, when they destroy all the foliage, all the tree and bush covers from their positions. Will it look like WWI with trenches running parallel with a nomansland in between?