Negative confirmations, block height not syncing

[MrNaif2018]

I am writing app using electrum version 3.3.2 in python. My task is to get confirmations of bitcoin transaction. I get it as current block height minus block height of transaction, because(maybe it is a bug too) wallet(electrum.Wallet object).get_tx_height(tx_hash_passed_here) always returns 0 confirmations,for both my wallet and non wallet transactions,but tx height is correct. It works fine just after restart,but after some time(half a day or so),it stops syncing block height. For getting block height I don't use wallet.local_height() or similar,because they also return incorrect results. I get height as in block_headers.py script example in source tree, with some modifications done after asking in electrum group.
Code is the following:

from electrum.network import Network
from electrum.util import create_and_start_event_loop
#block_headers.py start

# start network
loop, stopping_fut, loop_thread = create_and_start_event_loop()
network = Network()
network.start()

# wait until connected
while not network.is_connected():
    time.sleep(1)

header_queue = asyncio.Queue()

timer=time.time()
 
async def update_height():
    global height_blocks
    try:
        await network.interface.session.subscribe('blockchain.headers.subscribe', [], header_queue)
        while True:
            if network.is_connected():
                timer=time.time()
                header = await header_queue.get()
                max_height=-99999999
                for i in header:
                    if i["height"] > max_height:
                        max_height=i["height"]
                height_blocks=max_height
            else:
                if time.time() - timer > 10:
                    timer=time.time()
                    network.stop() # check with and without: may not be required
                    network.start()
    finally:
        stopping_fut.set_result(1)

#block_headers.py end

And confirmations I get the following way:
conf=height_blocks-height+1
So confirmations are negative because of electrum not syncing height.

[MrNaif2018]

Also,when looking at logs, I found some traceback from electrum(looks like from its network thread),maybe it will help. Probably it is because I have just removed blockhain_headers as suggested in other conversation. But still looking for help(is it a bug or not,seems to be a bug).
Here it is the error traceback:
https://imgur.com/a/YALcKg8

[MrNaif2018]

Small bump! Sorry for this,but this issue is a bug and I thought to get some answers what is it. And on forums(bitcointalk) I was even said that negative confirmations is quite common problem. If it is not a bug,please,give me solution to this problem,as I couldn't get support in IRC group.

[SomberNight]

My task is to get confirmations of bitcoin transaction

See the get_tx_status RPC in 8f5ca40
for wallet-related transactions.