Adding twice in hash table in C - c

Question

Based on print statements in the rehashing section, I can see that the same string is getting added to the table multiple times. I believe the problem is in this function, although I can't see where. The print statement below return is never executed, so I know that the function actually executes.
Any ideas on where the problem is, or how I should go about finding it? Thanks. The full code on our repository is here:
https://github.com/csking1/buddhism/blob/master/Finding/hash_tables.c
void add_to_table(HashTable *h, char* str, LinkedList* new){
unsigned int hashval = hash(h, str);
LinkedList *list;
// walk through the table and check for the first free spot, start at hash val and go to the top
for (int i = hashval; i<h->size; i++){
list = h->table[i];
if (list == NULL){
new->next = h->table[i];
h->table[i] = new;
new->string = str;
return;
printf("%s\n", "didn't return");
}
}
// start at the bottom of the table, check for the first free spot up to hash val, then return
for (int i = 0; i < hashval; i++){
list = h->table[i];
if (list == NULL){
new->next = h->table[i];
h->table[i] = new;
new->string = str;
return;
}
}
}
For a full view, here's the string lookup function. This gets called one or two lines above the add_to_table() function, and returns if the string is already there.
LinkedList *lookup_string(HashTable *h, char *str){
LinkedList *list;
unsigned int hashval = hash(h, str);
for (int i = hashval; i < h->size; i++){
list = h->table[i];
if (list == NULL){
return NULL;
}
if (list != NULL){
if (strcmp(str, list->string) == 0){
return list;
}
}
}
for (int i = 0; i < hashval; i++){
list = h->table[i];
if (list == NULL){
return NULL;
}
if (list != NULL){
if (strcmp(str, list->string) == 0){
return list;
}
}
}
return NULL;
}