Real time FFT & IFFT with low pass filter

I am processing the signal from MPU6050. Applying FIR filter in the frequency domain and then taking IFFT to get filtered signal but getting some spikes in the output signal. Searched a lot about it and found here exit spectral leakage. Found some solutions like zero paddings and windowing but nothing is working. Can some one take a look and let me know what I am doing wrong here.

Here is what I am getting

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Complete Code

close all; clear all ;clc; delete(instrfindall); 
arduino=serial('COM6','BAUD', 115200); 
fopen(arduino); 
java.lang.Thread.sleep(0.01);  % in mysec!

samples = pow2(nextpow2(5000))
sig = []; out_sig =[0];  tic;    G=0;    trying=0;  pingpong = 0;
while 1
    idn = fscanf(arduino);
    xx = str2double(idn);
    if isnan(xx)
        fclose(arduino);
        java.lang.Thread.sleep(1);  % in mysec!
        fopen(arduino);
        java.lang.Thread.sleep(1);  % in mysec!
        trying  = trying + 1
        continue
    else
        sig = [sig  xx];
    end
    if length(sig)>samples - 1
        break
    end
end
fclose(arduino);
plot(sig,'g');      %---------------------------->Orginal signal <---------------------------
hold on 
PG = plot(out_sig,'k');  %---------------------------->Output signal <---------------------------
PG.YDataSource = 'out_sig';

SegmentLength = pow2(nextpow2(1000))  % Transform length to next pow of 2
Fs = SegmentLength; 

wiin = hann(64,'symmetric');
filtcoeff  = fir1(63, 20/Fs, 'low', wiin, 'scale');
firfilterimpresp = impz(filtcoeff);
filterffte = fft(firfilterimpresp,SegmentLength); % FFT of impulse response of filter/system

ChunkStart = 1;
ChunkEnd = SegmentLength;
sigblock = [];
for t = 1:samples/SegmentLength
    sigblock = sig(ChunkStart:ChunkEnd);
    blockfft = fft(sigblock,SegmentLength);
    out_sigg = real(ifft(blockfft.*filterffte'));
    out_sig = [out_sig out_sigg];
    
    refreshdata
    drawnow
    ChunkStart = ChunkEnd;
    ChunkEnd = ChunkEnd + SegmentLength -1 ;
end

[Star Strider]

If you want to filter in the frequency domain, the Signal Processing Toolbox has the fftfilt function.

[Ans Hafeez]

Added following lines of code but getting same prooblem

DesignedFilt = designfilt('lowpassfir', 'FilterOrder', 32,'CutoffFrequency', 20, 'SampleRate', Fs);
out_sigg = fftfilt(DesignedFilt,sigblock,SegmentLength);