Copy from Google Chrome doesn't paste all contents

In ubuntu 20.04 I try to copy a block of Google Colabratory opened in Chrome:

This was copied from Firefox, which is the complete text:

import fastai
from fastai.core import PathOrStr
from fastai.text.data import ListRules, get_default_size, quotemark, full_char_coverage_langs
from typing import Collection

def train_sentencepiece(texts:Collection[str], path:PathOrStr, pre_rules: ListRules=None, post_rules:ListRules=None,
    vocab_sz:int=None, max_vocab_sz:int=30000, model_type:str='unigram', max_sentence_len:int=20480, lang='en',
    char_coverage=None, tmp_dir='tmp', enc='utf8'):
    "Train a sentencepiece tokenizer on `texts` and save it in `path/tmp_dir`"
    from sentencepiece import SentencePieceTrainer
    cache_dir = Path(path)/tmp_dir
    cache_dir = Path("data/wiki/fa-2/models/fsp15k")
    quotemark = ''
    print("It's me:", cache_dir)
    os.makedirs(cache_dir, exist_ok=True)
    if vocab_sz is None: vocab_sz=get_default_size(texts, max_vocab_sz)
    raw_text_path = cache_dir / 'all_text.out'
    with open(raw_text_path, 'w', encoding=enc) as f: f.write("\n".join(texts))
    spec_tokens = ['\u2581'+s for s in defaults.text_spec_tok]
    SentencePieceTrainer.Train(" ".join([
        f"--input={quotemark}{raw_text_path}{quotemark} --max_sentence_length={max_sentence_len}",
        f"--character_coverage={ifnone(char_coverage, 0.99999 if lang in full_char_coverage_langs else 0.9998)}",
        f"--unk_id={len(defaults.text_spec_tok)} --pad_id=-1 --bos_id=-1 --eos_id=-1",
        f"--user_defined_symbols={','.join(spec_tokens)}",
        f"--model_prefix={cache_dir/'spm'} --hard_vocab_limit=false --vocab_size={vocab_sz} --model_type={model_type}"]))
    raw_text_path.unlink()
    return cache_dir
        
fastai.text.data.train_sentencepiece = train_sentencepiece

It's copied from Chrome:

import fastai
from fastai.core import PathOrStr
from fastai.text.data import ListRules, get_default_size, quotemark, full_char_coverage_langs
from typing import Collection

def train_sentencepiece(texts:Collection[str], path:PathOrStr, pre_rules: ListRules=None, post_rules:ListRules=None,
    vocab_sz:int=None, max_vocab_sz:int=30000, model_type:str='unigram', max_sentence_len:int=20480, lang='en',
    char_coverage=None, tmp_dir='tmp', enc='utf8'):
    "Train a sentencepiece tokenizer on `texts…",
        f"--character_coverage={ifnone(char_coverage, 0.99999 if lang in full_char_coverage_langs else 0.9998)}",
        f"--unk_id={len(defaults.text_spec_tok)} --pad_id=-1 --bos_id=-1 --eos_id=-1",
        f"--user_defined_symbols={','.join(spec_tokens)}",
        f"--model_prefix={cache_dir/'spm'} --hard_vocab_limit=false --vocab_size={vocab_sz} --model_type={model_type}"]))
    raw_text_path.unlink()
    return cache_dir
        
fastai.text.data.train_sentencepiece = train_sentencepiece

As you see, when I copy the block from Chrome and then paste it here, parts of the text is absent!!