Overly long toe nails could cause gate issue on a hard surface a soft surface link grass and dirt it is less likely.
I also think basset have a tendency to stumble at a walking gate more so than any other gate ie (trot, cantor or gallop). Toughy had a tendency to stumble when walking but when running agility did not have a problem.
I an not sure what you are trying to put into words but for every dog the foot would be the last thing tha moves so I am not sure what you are descirbing is abnormal to begin with. For basset that stumble on the front end in most incidents it appear to me to occur at the shoulder not at the feet. that is the toe clicking etc are the result of the stumble not the cause but of curse the only way to know for sure is taking the dog to the vet.
I also think basset have a tendency to stumble at a walking gate more so than any other gate ie (trot, cantor or gallop). Toughy had a tendency to stumble when walking but when running agility did not have a problem.