JIRA Python to select all issues from JIRA server

I have some code to connect to my company’s instance of the JIRA server via Jira’s Python Client. When i do a count on all the projects available in the server, I see close to 4300 projects, but when I loop through the projects to get a list of all the issues in all the projects, I cannot get more than 149 projects. There are about 100 issues in each project so I’d expect a total of 4300 projects and 430000 issues.
But I’m getting 149 projects and the loop exists with ~27000 issues. Has anyone faced this problem? Here’s the code I’m using:

import jira.client
from jira.client import JIRA
import re
import pandas as pd
options = {"server": "https://horizon.xxxxxx.com/issues",'verify':False}
jira = JIRA(options, basic_auth=('user','pwd'))
projects = jira.projects()
allissues = []
allprojects=[]
block_size=50
for projectA in projects:
    block_num=0
    while True:
        start_idx=block_num*block_size
        issues=jira.search_issues(f'project = {projectA.key}', start_idx, block_size)
        if len(issues)== 0:
            break
        block_num+=1
        for issue in issues:
            allissues.append(issue)
            allprojects.append(projectA.key)