As per my understanding it is not the best way to automate excel operation using ui automations.
Because you will face many issues like above… Sometome uipath not able to find the element.
Uipath support such kind of features so you can use vb scripts or java scripts to do some operations with excel
Such case you can use your coding skils by injecting other languages programs to uipath.
If your any issue related to ui automations , or if some where your not finding any work arounds then you can post it to forum any one will help.